From 3b480b9885a719284a2f5815a5dedb14dbf4ec4a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Bombeck?= <marc@bombeck.io>
Date: Thu, 11 Jun 2026 02:19:27 +0200
Subject: [PATCH] perf(i18n,shell): ship one locale and stop blocking the first
 paint
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The client bundle carries only the active locale — resolved on the
server and handed to the provider with no hydration flash, halving the
dashboard route to under a megabyte parsed (288 KiB gzip). The auth
shell renders the app chrome immediately instead of a spinner while the
session resolves in parallel, the widgets request folds into the
snapshot it duplicated, and insight pills prefetch their sub-pages —
a first visit to a sub-page lands in about ninety milliseconds instead
of nearly a second.
---
 docs/api/openapi.yaml                         |   66 +
 docs/ui-guidelines.md                         |   35 +-
 messages/de.json                              |   13 +
 messages/en.json                              |   13 +
 messages/es.json                              |   13 +
 messages/fr.json                              |   13 +
 messages/it.json                              |   13 +
 messages/pl.json                              |   13 +
 .../dashboard-analytics-split.test.ts         |    2 +-
 .../admin/audit-log/__tests__/route.test.ts   |    8 +-
 .../__tests__/route.test.ts                   |    2 +-
 .../notifications/reminder-check/route.ts     |    2 +-
 .../assistant-flags/__tests__/route.test.ts   |    2 +-
 .../admin/users/[id]/__tests__/route.test.ts  |    6 +-
 .../auth/check-user/__tests__/route.test.ts   |    8 +-
 .../auth/login/__tests__/native-token.test.ts |    6 +-
 .../me/devices/[id]/__tests__/route.test.ts   |    2 +-
 .../auth/me/devices/__tests__/route.test.ts   |    2 +-
 .../me/disable-coach/__tests__/route.test.ts  |    2 +-
 .../__tests__/route.test.ts                   |    6 +-
 .../__tests__/route.test.ts                   |    2 +-
 .../me/research-mode/__tests__/route.test.ts  |    2 +-
 .../source-priority/__tests__/route.test.ts   |    2 +-
 .../auth/me/timezone/__tests__/route.test.ts  |    2 +-
 .../unit-preference/__tests__/route.test.ts   |    2 +-
 .../__tests__/native-token.test.ts            |    4 +-
 .../api/consent/ai/__tests__/route.test.ts    |    2 +-
 .../consent/ai/latest/__tests__/route.test.ts |    2 +-
 .../dashboard/summary/__tests__/route.test.ts |    4 +-
 .../api/devices/[id]/__tests__/route.test.ts  |    2 +-
 src/app/api/devices/__tests__/route.test.ts   |    2 +-
 .../doctor-report/__tests__/pdf-route.test.ts |    2 +-
 .../api/doctor-report/availability/route.ts   |    2 +-
 .../api/feature-flags/__tests__/route.test.ts |    2 +-
 .../__tests__/hidden-redaction.test.ts        |    2 +-
 .../achievements/__tests__/ios-format.test.ts |    2 +-
 .../[jobId]/status/__tests__/route.test.ts    |    4 +-
 .../__tests__/route.test.ts                   |    2 +-
 .../__tests__/route.test.ts                   |    2 +-
 .../insights/cards/__tests__/route.test.ts    |    2 +-
 .../comprehensive/__tests__/route.test.ts     |    2 +-
 .../correlations/__tests__/route.test.ts      |    2 +-
 src/app/api/insights/correlations/route.ts    |    4 +-
 .../insights/derived/__tests__/route.test.ts  |    2 +-
 .../derived/batch/__tests__/route.test.ts     |    2 +-
 .../insights/generate/__tests__/route.test.ts |    2 +-
 .../metric-status/__tests__/route.test.ts     |    2 +-
 .../pregenerate/__tests__/route.test.ts       |    2 +-
 .../rhythm-events/__tests__/route.test.ts     |    2 +-
 .../insights/targets/__tests__/route.test.ts  |    2 +-
 .../healthkit/__tests__/route.test.ts         |    2 +-
 .../__tests__/route.test.ts                   |    2 +-
 .../__tests__/put-duplicate-timestamp.test.ts |    2 +-
 .../__tests__/range-aggregation-route.test.ts |    2 +-
 .../batch/__tests__/pr-detection-hook.test.ts |    2 +-
 .../restore/__tests__/route.test.ts           |  177 ++
 src/app/api/measurements/restore/route.ts     |  144 ++
 src/app/api/measurements/route.ts             |    4 +-
 .../series/__tests__/route.test.ts            |    2 +-
 .../[id]/cadence/__tests__/route.test.ts      |    2 +-
 .../[id]/compliance/__tests__/route.test.ts   |    4 +-
 .../[id]/dose-history/__tests__/route.test.ts |    4 +-
 .../[id]/glp1/__tests__/route.test.ts         |    2 +-
 .../intake/[eventId]/__tests__/route.test.ts  |    2 +-
 .../[id]/intake/__tests__/route.test.ts       |    2 +-
 .../bulk-delete/__tests__/route.test.ts       |    2 +-
 .../[id]/inventory/__tests__/route.test.ts    |    2 +-
 src/app/api/medications/[id]/route.ts         |    2 +-
 .../[id]/side-effects/[logId]/route.ts        |    2 +-
 .../[id]/side-effects/__tests__/route.test.ts |    2 +-
 .../api/medications/__tests__/route.test.ts   |    2 +-
 .../intake/__tests__/route.test.ts            |    2 +-
 src/app/api/medications/intake/route.ts       |    2 +-
 src/app/api/medications/route.ts              |    2 +-
 .../restore/__tests__/route.test.ts           |  161 ++
 src/app/api/mood-entries/restore/route.ts     |  133 ++
 .../mood/analytics/__tests__/route.test.ts    |    2 +-
 .../status/__tests__/route.test.ts            |    2 +-
 src/app/api/onboarding/__tests__/step.test.ts |    2 +-
 .../personal-records/__tests__/route.test.ts  |    2 +-
 .../api/sleep/night/__tests__/route.test.ts   |    2 +-
 .../api/user/profile/__tests__/route.test.ts  |   16 +-
 .../workouts/__tests__/batch-create.test.ts   |    2 +-
 .../__tests__/canonical-dedup.test.ts         |    2 +-
 src/app/api/workouts/__tests__/detail.test.ts |    2 +-
 src/app/auth/login/page.tsx                   |   78 +-
 src/app/auth/register/page.tsx                |   32 +-
 src/app/bugreport/page.tsx                    |   56 +-
 src/app/insights/medications/page.tsx         |   27 +-
 src/app/insights/mood/page.tsx                |    6 +-
 src/app/insights/page.tsx                     |   12 +-
 src/app/layout.tsx                            |   10 +-
 src/app/medications/[id]/page.tsx             |    5 +-
 src/app/medications/page.tsx                  |    6 +-
 src/app/notifications/page.tsx                |   14 +-
 src/app/onboarding/[step]/page.tsx            |    2 +-
 src/app/page.tsx                              |   19 +-
 src/app/privacy/__tests__/page.test.tsx       |    9 +-
 .../__tests__/ai-quality-section.test.tsx     |    2 +-
 .../__tests__/api-token-no-collapse.test.tsx  |    4 +-
 .../api-token-overview-responsive.test.tsx    |    8 +-
 .../__tests__/api-token-truncate.test.tsx     |    8 +-
 .../app-log-preview-summary-position.test.tsx |    4 +-
 .../__tests__/backups-section-empty.test.tsx  |    2 +-
 .../__tests__/coach-feedback-section.test.tsx |    2 +-
 .../login-overview-auth-filter.test.tsx       |    4 +-
 .../__tests__/login-overview-csv.test.ts      |   24 +-
 .../login-overview-no-collapse.test.tsx       |    4 +-
 ...ogin-overview-pagination-position.test.tsx |    6 +-
 .../login-overview-provider.test.tsx          |    2 +-
 .../admin/__tests__/sections.test.tsx         |    6 +-
 .../admin/__tests__/status-card-grid.test.tsx |    8 +-
 .../__tests__/user-management-empty.test.tsx  |    4 +-
 .../user-management-responsive.test.tsx       |    8 +-
 src/components/admin/_shared.tsx              |   24 +-
 src/components/admin/ai-quality-section.tsx   |   14 +-
 .../admin/api-token-overview-section.tsx      |    7 +-
 .../admin/app-log-preview-section.tsx         |    5 +-
 src/components/admin/assistant-section.tsx    |   17 +-
 src/components/admin/backups-section.tsx      |   45 +-
 .../admin/coach-feedback-section.tsx          |   16 +-
 src/components/admin/danger-zone-section.tsx  |   12 +-
 .../admin/feedback-inbox-section.tsx          |   26 +-
 src/components/admin/glitchtip-section.tsx    |   14 +-
 src/components/admin/host-metrics-chart.tsx   |    5 +-
 .../admin/invite-tokens-section.tsx           |   36 +-
 .../admin/login-overview-section.tsx          |    9 +-
 src/components/admin/recent-audit-preview.tsx |    7 +-
 src/components/admin/reminders-section.tsx    |   85 +-
 src/components/admin/umami-section.tsx        |   14 +-
 .../admin/user-management-section.tsx         |   61 +-
 src/components/admin/version-tile-section.tsx |   11 +-
 src/components/app-settings-provider.tsx      |    6 +-
 .../health-chart-empty-state-gate.test.tsx    |    6 +-
 .../health-chart-no-data-in-range.test.tsx    |    6 +-
 .../health-chart-overlay-defaults.test.tsx    |    2 +-
 ...compliance-chart-empty-state-gate.test.tsx |    8 +-
 .../mood-chart-empty-state-gate.test.tsx      |    8 +-
 .../__tests__/mood-chart-polish.test.tsx      |    4 +-
 .../trend-card-baseline-alignment.test.tsx    |    2 +-
 .../charts/chart-overlay-controls.tsx         |    2 +-
 src/components/charts/health-chart.tsx        |   33 +-
 .../charts/medication-compliance-chart.tsx    |    8 +-
 src/components/charts/mood-chart.tsx          |    6 +-
 src/components/charts/trend-card.tsx          |    2 +-
 src/components/comparison/compare-toggle.tsx  |   14 +-
 src/components/cycle/log-day-sheet.tsx        |   55 +-
 src/components/cycle/use-cycle.ts             |  137 +-
 .../medication-intake-quick-add.test.tsx      |    4 +-
 .../dashboard/medication-intake-quick-add.tsx |   39 +-
 .../doctor-report/doctor-report-dialog.tsx    |   37 +-
 .../__tests__/health-score-card.test.tsx      |    2 +-
 .../__tests__/coach-input.test.tsx            |    2 +-
 .../__tests__/message-thread.test.tsx         |    4 +-
 .../insights/coach-panel/message-thread.tsx   |   31 +-
 .../coach-panel/self-context-adopt-offer.tsx  |    9 +-
 .../coach-panel/self-context-chips.tsx        |   19 +-
 .../insights/coach-panel/sources-rail.tsx     |    8 +-
 .../insights/coach-panel/use-coach.ts         |   32 +-
 .../insights/derived/use-derived-metric.ts    |   18 +-
 src/components/insights/health-score-card.tsx |    2 +-
 .../insights/insights-edit-mode.tsx           |   15 +-
 .../insights/insights-layout-shell.tsx        |    6 +-
 .../insights/insights-tab-strip.tsx           |   12 +-
 src/components/insights/layout-coach-fab.tsx  |    5 +-
 .../insights/measurement-diversity-nudge.tsx  |   17 +-
 .../insights/metric-target-summary.tsx        |    6 +-
 .../insights/mood/mood-insights-sections.tsx  |    6 +-
 .../insights/mood/mood-what-stands-out.tsx    |    9 +-
 .../insights/period-narrative-card.tsx        |    7 +-
 .../insights/personal-record-badge.tsx        |   15 +-
 .../insights/recommendation-feedback.tsx      |   28 +-
 .../insights/rhythm-events-card.tsx           |   12 +-
 src/components/insights/sleep-hypnogram.tsx   |    2 +-
 src/components/insights/sleep-overview.tsx    |    7 +-
 .../insights/sleep-stage-stacked-bar.tsx      |    2 +-
 src/components/insights/trend-annotation.tsx  |   14 +-
 .../insights/use-insights-advisor.ts          |    8 +-
 .../layout/__tests__/sidebar-nav.test.tsx     |    4 +-
 src/components/layout/auth-shell.tsx          |   43 +-
 src/components/layout/sidebar-nav.tsx         |    1 -
 ...asurement-list-apple-health-badge.test.tsx |    2 +-
 .../measurement-list-bp-badge.test.tsx        |    2 +-
 .../__tests__/measurement-list-empty.test.tsx |    2 +-
 .../measurement-list-filter-select.test.tsx   |    2 +-
 .../measurement-list-locked-type.test.tsx     |    2 +-
 .../measurement-list-step-grouping.test.tsx   |    2 +-
 .../measurements/measurement-form.tsx         |   45 +-
 .../measurements/measurement-list.tsx         |  119 +-
 src/components/medications/DrugLevelChart.tsx |   25 +-
 .../ResearchModeAcknowledgmentDialog.tsx      |   23 +-
 .../medications/SideEffectsSection.tsx        |   29 +-
 .../ResearchModeAcknowledgmentDialog.test.tsx |    4 +-
 .../medications/__tests__/card-parts.test.tsx |    4 +-
 .../__tests__/intake-history-list-v2.test.tsx |    4 +-
 .../__tests__/use-medication-intake.test.ts   |   30 +-
 .../card-parts/medication-card-body.tsx       |    2 +-
 .../detail/MedicationDetailTabs.tsx           |   51 +-
 .../medications/dose-history-add-dialog.tsx   |  153 +-
 .../medications/dose-history-ledger.tsx       |   89 +-
 .../medications/dose-strength-curve.tsx       |   12 +-
 .../medications/glp1-medication-card.tsx      |   49 +-
 .../medications/intake-edit-dialog.tsx        |  147 +-
 .../medications/intake-history-editable.tsx   |   24 +-
 .../medications/intake-history-list-v2.tsx    |    9 +-
 .../medications/intake-import-dialog.tsx      |   24 +-
 .../medications/log-intake-dialog.tsx         |   14 +-
 .../medications/medication-card.tsx           |   38 +-
 .../scheduling/DoseWindowEditor.tsx           |    2 +-
 .../scheduling/ScheduleTimesEditor.tsx        |   11 +-
 .../medications/scheduling/dose-window.ts     |    2 +-
 .../medications/sections/api-tokens-row.tsx   |   47 +-
 .../sections/destructive-zone-section.tsx     |   39 +-
 .../sections/inventory-section.tsx            |   38 +-
 .../sections/notifications-section.tsx        |   20 +-
 .../sections/phase-config-sheet.tsx           |   31 +-
 .../medications/sections/settings-section.tsx |   25 +-
 .../medications/use-medication-intake.ts      |   63 +-
 .../medications/wizard/steps/Step2Class.tsx   |    2 +-
 .../medications/wizard/steps/Step8Summary.tsx |    9 +-
 .../medications/wizard/wizard-payload.ts      |    2 +-
 src/components/monitoring/bootstrap.tsx       |   12 +-
 .../monitoring/glitchtip-reporter.tsx         |   15 +-
 .../mood-list-filter-select.test.tsx          |    2 +-
 src/components/mood/mood-form.tsx             |   36 +-
 src/components/mood/mood-list.tsx             |   73 +-
 src/components/mood/mood-tag-picker.tsx       |    6 +-
 src/components/onboarding/BaselineForm.tsx    |   16 +-
 src/components/onboarding/GoalsChipPicker.tsx |    9 +-
 src/components/onboarding/SourceCardGrid.tsx  |    9 +-
 src/components/onboarding/WelcomeCarousel.tsx |    9 +-
 .../onboarding/getting-started-checklist.tsx  |   18 +-
 src/components/onboarding/tour-launcher.tsx   |    7 +-
 src/components/providers.tsx                  |    8 +-
 .../settings/__tests__/ai-section.test.tsx    |    2 +-
 .../__tests__/api-section-responsive.test.tsx |    4 +-
 .../__tests__/disable-coach-card.test.tsx     |    4 +-
 .../__tests__/integrations-section.test.tsx   |    2 +-
 .../settings/__tests__/sections.test.tsx      |    6 +-
 src/components/settings/about-me-section.tsx  |   17 +-
 src/components/settings/about-section.tsx     |    8 +-
 src/components/settings/account-section.tsx   |   36 +-
 src/components/settings/advanced-section.tsx  |    9 +-
 src/components/settings/ai-section.tsx        | 1973 +----------------
 .../ai/admin-openai-provider-form.tsx         |   27 +
 .../settings/ai/ai-insights-card.tsx          |  311 +++
 .../settings/ai/anthropic-provider-form.tsx   |  171 ++
 .../settings/ai/codex-provider-form.tsx       |  298 +++
 .../settings/ai/disable-coach-card.tsx        |  157 ++
 .../settings/ai/fallback-chain-card.tsx       |  320 +++
 .../settings/ai/local-provider-form.tsx       |  172 ++
 .../settings/ai/openai-provider-form.tsx      |  208 ++
 .../settings/ai/runtime-actions-row.tsx       |  274 +++
 src/components/settings/ai/shared.ts          |  142 ++
 src/components/settings/api-section.tsx       |   11 +-
 .../settings/coach-memory-section.tsx         |   31 +-
 src/components/settings/coach-nudge-card.tsx  |    7 +-
 .../settings/cycle-tracking-card.tsx          |   13 +-
 .../settings/dashboard-layout-section.tsx     |   20 +-
 src/components/settings/export-section.tsx    |    9 +-
 .../settings/health-record-export-panel.tsx   |    3 +-
 src/components/settings/import-panel.tsx      |   14 +-
 .../settings/injection-sites-card.tsx         |   10 +-
 .../settings/insights-pill-order-section.tsx  |   11 +-
 .../settings/integrations-section.tsx         | 1509 +------------
 .../settings/integrations/fitbit-card.tsx     |  483 ++++
 .../settings/integrations/shared.tsx          |  142 ++
 .../settings/integrations/whoop-card.tsx      |  455 ++++
 .../settings/integrations/withings-card.tsx   |  497 +++++
 .../settings/mood-reminder-card.tsx           |   13 +-
 .../settings/notification-status-card.tsx     |   16 +-
 .../settings/notifications-section.tsx        |    5 +-
 src/components/settings/ntfy-card.tsx         |    8 +-
 src/components/settings/sources-section.tsx   |   24 +-
 src/components/settings/telegram-card.tsx     |    8 +-
 .../settings/thresholds-editor-section.tsx    |    8 +-
 .../settings/time-format-select.tsx           |    3 +-
 .../settings/unit-preference-select.tsx       |    3 +-
 src/components/settings/web-push-card.tsx     |    7 +-
 src/components/targets/consistency-strip.tsx  |    2 +-
 src/components/targets/target-edit-sheet.tsx  |   42 +-
 src/components/ui/__tests__/tabs.test.tsx     |    2 +-
 src/components/version-poller.tsx             |   18 +-
 vitest.setup.ts                               |   26 +
 284 files changed, 6058 insertions(+), 5398 deletions(-)
 create mode 100644 src/app/api/measurements/restore/__tests__/route.test.ts
 create mode 100644 src/app/api/measurements/restore/route.ts
 create mode 100644 src/app/api/mood-entries/restore/__tests__/route.test.ts
 create mode 100644 src/app/api/mood-entries/restore/route.ts
 create mode 100644 src/components/settings/ai/admin-openai-provider-form.tsx
 create mode 100644 src/components/settings/ai/ai-insights-card.tsx
 create mode 100644 src/components/settings/ai/anthropic-provider-form.tsx
 create mode 100644 src/components/settings/ai/codex-provider-form.tsx
 create mode 100644 src/components/settings/ai/disable-coach-card.tsx
 create mode 100644 src/components/settings/ai/fallback-chain-card.tsx
 create mode 100644 src/components/settings/ai/local-provider-form.tsx
 create mode 100644 src/components/settings/ai/openai-provider-form.tsx
 create mode 100644 src/components/settings/ai/runtime-actions-row.tsx
 create mode 100644 src/components/settings/ai/shared.ts
 create mode 100644 src/components/settings/integrations/fitbit-card.tsx
 create mode 100644 src/components/settings/integrations/shared.tsx
 create mode 100644 src/components/settings/integrations/whoop-card.tsx
 create mode 100644 src/components/settings/integrations/withings-card.tsx
 create mode 100644 vitest.setup.ts

diff --git a/docs/api/openapi.yaml b/docs/api/openapi.yaml
index ef09fc52e..5e97c78b7 100644
--- a/docs/api/openapi.yaml
+++ b/docs/api/openapi.yaml
@@ -1735,6 +1735,31 @@ paths:
         "401": *a1
         "422": *a3
         "429": *a4
+  /api/measurements/restore:
+    post:
+      tags:
+        - Measurements
+      summary: Restore soft-deleted measurements
+      description: Un-tombstones up to 200 of the caller's soft-deleted measurement rows in one call — the delete-Undo
+        counterpart to `/api/measurements/bulk-delete`. Idempotent via the `Idempotency-Key` header; rate-limited
+        `measurements:restore:<userId>`. Forged / foreign / not-deleted ids are silently skipped — `restored` is the
+        count of rows actually un-tombstoned. The restored rows re-surface in `/api/sync/changes` as upserts.
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/MeasurementsRestoreRequest"
+      responses:
+        "200":
+          description: Restore processed.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/MeasurementsRestoreResponse"
+        "401": *a1
+        "422": *a3
+        "429": *a4
   /api/sleep/night:
     get:
       tags:
@@ -4229,6 +4254,20 @@ components:
       required:
         - ids
       description: 1..200 measurement ids, scoped to the caller. Forged / foreign ids are silently skipped (no existence leak).
+    MeasurementsRestoreRequest:
+      type: object
+      properties:
+        ids:
+          minItems: 1
+          maxItems: 200
+          type: array
+          items:
+            type: string
+            minLength: 1
+      required:
+        - ids
+      description: 1..200 measurement ids, scoped to the caller. Forged / foreign / not-deleted ids are silently skipped (no
+        existence leak).
     DeviceRegisterRequest:
       type: object
       properties:
@@ -7323,6 +7362,33 @@ components:
       required:
         - deleted
       additionalProperties: false
+    MeasurementsRestoreResponse:
+      type: object
+      properties:
+        data:
+          $ref: "#/components/schemas/MeasurementsRestoreResult"
+        error:
+          type: "null"
+        meta:
+          type: object
+          properties:
+            requestId:
+              type: string
+          additionalProperties: false
+      required:
+        - data
+        - error
+      additionalProperties: false
+    MeasurementsRestoreResult:
+      type: object
+      properties:
+        restored:
+          type: integer
+          minimum: 0
+          maximum: 9007199254740991
+      required:
+        - restored
+      additionalProperties: false
     SleepNightResponse:
       type: object
       properties:
diff --git a/docs/ui-guidelines.md b/docs/ui-guidelines.md
index fcb14b166..3e58b9069 100644
--- a/docs/ui-guidelines.md
+++ b/docs/ui-guidelines.md
@@ -149,9 +149,38 @@ Wrap inputs in `<label>` (visible) plus `aria-describedby` for helper text.
   _and_ the user routinely sweeps. For most thresholds and counts, an
   `<Input type="number">` plus stepper buttons is faster and less
   fiddly. See §6 (Slider audit) for the migration path.
-- **Boolean toggle**: `<Switch>` for "applies immediately" settings (e.g.
-  enable Telegram). `<Checkbox>` for "applies on Save" lists (e.g. select
-  measurements to export).
+- **Boolean toggle**: `<Switch>` for settings. Exactly two persistence
+  patterns are legal (see §2.2.1); pick one per card, never mix.
+  `<Checkbox>` stays reserved for "applies on Save" _lists_ (e.g. select
+  measurements to export) and for action parameters that are not
+  persisted at all (export options).
+
+#### 2.2.1 Settings persistence patterns
+
+Every control under `/settings` follows exactly one of two save
+patterns. The pattern is a property of the **card**, not of the
+individual control:
+
+1. **Immediate persist** — a standalone boolean that is the card's only
+   mutable state. The `<Switch>` fires the mutation in
+   `onCheckedChange`, disables itself while pending, updates
+   optimistically with rollback, and toasts on success/error. No Save
+   button anywhere on the card. Examples: hide-Coach, ntfy enable,
+   cycle tracking, research mode, mood reminder, Coach nudges.
+2. **Draft + Save** — the card edits a multi-field payload (or a list
+   the server PUTs whole). All controls — including `<Switch>` rows —
+   mutate a local draft only; a visible Save button flushes the draft
+   in one request and the card surfaces its dirty state. Examples:
+   Coach preferences, Telegram (enable + bot token), provider fallback
+   chain, dashboard layout, threshold editor.
+
+A `<Switch>` inside a draft+Save card is legal **only** when the card
+shows the Save button; a card with both an auto-persisting switch and
+a Save-gated field is a bug. Every setting presented under `/settings`
+persists server-side. `localStorage` is reserved for device-local UI
+state that is not a setting (sidebar collapse, last-update-check
+timestamp, tour progress) — label such keys with a comment at the
+declaration site and never render them with Save/Saved affordances.
 
 **Validation.** Inline messages below the field. Field gets
 `aria-invalid="true"` and a destructive border. Form-level errors land
diff --git a/messages/de.json b/messages/de.json
index a28c7b2f9..f914ea15f 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -3,6 +3,7 @@
     "save": "Speichern",
     "cancel": "Abbrechen",
     "delete": "Löschen",
+    "undo": "Rückgängig",
     "edit": "Bearbeiten",
     "moreOptions": "Weitere Optionen",
     "create": "Erstellen",
@@ -449,6 +450,9 @@
     "saveError": "Fehler beim Speichern",
     "duplicateTimestamp": "Zum gewählten Zeitpunkt existiert bereits ein Messwert dieses Typs.",
     "deleteError": "Fehler beim Löschen",
+    "deletedToast": "Messwert gelöscht",
+    "restoredToast": "Messwert wiederhergestellt",
+    "restoreError": "Wiederherstellen fehlgeschlagen",
     "invalidValue": "Bitte einen gültigen Wert eingeben.",
     "invalidTimestamp": "Bitte einen gültigen Zeitpunkt wählen.",
     "loginRequired": "Bitte anmelden, um Messwerte zu sehen.",
@@ -547,6 +551,9 @@
     "formResetConfirmAction": "Zurücksetzen",
     "saveError": "Fehler beim Speichern",
     "deleteError": "Fehler beim Löschen",
+    "deletedToast": "Eintrag gelöscht",
+    "restoredToast": "Eintrag wiederhergestellt",
+    "restoreError": "Wiederherstellen fehlgeschlagen",
     "invalidTimestamp": "Bitte einen gültigen Zeitpunkt wählen.",
     "deleteConfirmTitle": "Eintrag löschen?",
     "deleteConfirmDescription": "Dieser Stimmungseintrag wird unwiderruflich gelöscht.",
@@ -806,6 +813,7 @@
       "loading": "Wird geladen…",
       "deleteCta": "Löschen",
       "deleteConfirm": "Eintrag löschen?",
+      "deleteError": "Eintrag konnte nicht gelöscht werden",
       "errorSeverity": "Schweregrad muss zwischen 1 und 5 liegen",
       "errorEntry": "Bitte ein Symptom auswählen",
       "categories": {
@@ -1975,6 +1983,7 @@
       "errorBudget": "Du hast das heutige Coach-Limit erreicht. Das Budget setzt sich um Mitternacht (UTC) zurück.",
       "errorProvider": "Der Coach konnte gerade keinen Auswertungs-Anbieter erreichen. Bitte versuche es in einem Moment erneut.",
       "errorNetwork": "Keine Internetverbindung — versuche es erneut, sobald du online bist.",
+      "prefsSaveError": "Coach-Einstellungen konnten nicht gespeichert werden. Bitte versuche es erneut.",
       "errorCredentialExpired": "Deine Verbindung zum KI-Anbieter ist abgelaufen. Stelle sie in den Einstellungen wieder her, damit der Coach weiterläuft.",
       "tagline": "Persönlicher Gesundheitscoach, auf deine Daten gestützt.",
       "newChat": "Neuer Chat",
@@ -1995,6 +2004,7 @@
         "failed": "Übernahme fehlgeschlagen. Bitte erneut versuchen."
       },
       "selfContextChipDismiss": "Frage verwerfen",
+      "selfContextChipDismissError": "Frage konnte nicht ausgeblendet werden",
       "voiceComingSoon": "Spracheingabe kommt mit der iOS-App in v1.5.",
       "threadEmpty": "Frag mich etwas zu deinen Trends, Medikamenten oder Messwerten, um zu starten.",
       "historyTitle": "Unterhaltungen",
@@ -2085,6 +2095,7 @@
       "feedbackHelpful": "Hilfreich",
       "feedbackUnhelpful": "Nicht ganz",
       "feedbackThanks": "Danke für das Signal.",
+      "feedbackError": "Feedback konnte nicht gespeichert werden",
       "dailyLimitTitle": "Heute-Limit erreicht",
       "dailyLimitBody": "Heute-Limit erreicht; Reset um 00:00 UTC.",
       "providerRateLimitTitle": "Provider rate-limited",
@@ -5641,6 +5652,8 @@
       "EMERGENCY": "Notfall"
     },
     "loadError": "Zyklusdaten konnten nicht geladen werden.",
+    "saveError": "Zykluseintrag konnte nicht gespeichert werden.",
+    "deleteError": "Eintrag konnte nicht gelöscht werden.",
     "bbt": {
       "title": "Basaltemperatur",
       "caption": "Deine Morgentemperatur über diesen Zyklus. Ein anhaltender Anstieg um etwa 0,2 °C folgt auf den Eisprung.",
diff --git a/messages/en.json b/messages/en.json
index 00f08266f..d2dbe17c9 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -3,6 +3,7 @@
     "save": "Save",
     "cancel": "Cancel",
     "delete": "Delete",
+    "undo": "Undo",
     "edit": "Edit",
     "moreOptions": "More options",
     "create": "Create",
@@ -449,6 +450,9 @@
     "saveError": "Error saving",
     "duplicateTimestamp": "A measurement of this type already exists at the selected timestamp.",
     "deleteError": "Error deleting",
+    "deletedToast": "Measurement deleted",
+    "restoredToast": "Measurement restored",
+    "restoreError": "Restore failed",
     "invalidValue": "Please enter a valid value.",
     "invalidTimestamp": "Please select a valid time.",
     "loginRequired": "Please sign in to view measurements.",
@@ -547,6 +551,9 @@
     "formResetConfirmAction": "Reset",
     "saveError": "Error saving",
     "deleteError": "Error deleting",
+    "deletedToast": "Entry deleted",
+    "restoredToast": "Entry restored",
+    "restoreError": "Restore failed",
     "invalidTimestamp": "Please select a valid time.",
     "deleteConfirmTitle": "Delete entry?",
     "deleteConfirmDescription": "This mood entry will be permanently deleted.",
@@ -806,6 +813,7 @@
       "loading": "Loading…",
       "deleteCta": "Delete",
       "deleteConfirm": "Delete this entry?",
+      "deleteError": "Could not delete the entry",
       "errorSeverity": "Severity must be between 1 and 5",
       "errorEntry": "Pick a symptom",
       "categories": {
@@ -1975,6 +1983,7 @@
       "errorBudget": "You've reached today's Coach usage limit. The budget refreshes at midnight UTC.",
       "errorProvider": "The Coach could not reach an Insights provider just now. Please try again in a moment.",
       "errorNetwork": "No internet connection — try again once you're back online.",
+      "prefsSaveError": "Couldn't save your Coach preferences. Please try again.",
       "errorCredentialExpired": "Your AI provider connection has expired. Reconnect it in Settings to keep the Coach running.",
       "tagline": "Personal health coach, grounded in your data.",
       "newChat": "New chat",
@@ -1995,6 +2004,7 @@
         "failed": "Could not add. Please try again."
       },
       "selfContextChipDismiss": "Dismiss question",
+      "selfContextChipDismissError": "Could not dismiss the question",
       "voiceComingSoon": "Voice input arrives with the iOS app in v1.5.",
       "threadEmpty": "Ask anything about your trends, medications, or readings to start a conversation.",
       "historyTitle": "Conversations",
@@ -2085,6 +2095,7 @@
       "feedbackHelpful": "Helpful",
       "feedbackUnhelpful": "Not quite",
       "feedbackThanks": "Thanks for the signal.",
+      "feedbackError": "Could not save feedback",
       "dailyLimitTitle": "Daily limit reached",
       "dailyLimitBody": "Daily limit reached; resets at 00:00 UTC.",
       "providerRateLimitTitle": "Provider rate-limited",
@@ -5641,6 +5652,8 @@
       "EMERGENCY": "Emergency"
     },
     "loadError": "Couldn't load your cycle data.",
+    "saveError": "Couldn't save your cycle entry.",
+    "deleteError": "Couldn't delete the entry.",
     "bbt": {
       "title": "Basal body temperature",
       "caption": "Your morning temperature across this cycle. A sustained rise of about 0.2 °C follows ovulation.",
diff --git a/messages/es.json b/messages/es.json
index 97956b89a..06e2b4047 100644
--- a/messages/es.json
+++ b/messages/es.json
@@ -3,6 +3,7 @@
     "save": "Guardar",
     "cancel": "Cancelar",
     "delete": "Eliminar",
+    "undo": "Deshacer",
     "edit": "Editar",
     "moreOptions": "Más opciones",
     "create": "Crear",
@@ -449,6 +450,9 @@
     "saveError": "Error al guardar",
     "duplicateTimestamp": "Ya existe una medición de este tipo en la marca de tiempo seleccionada.",
     "deleteError": "Error al eliminar",
+    "deletedToast": "Medición eliminada",
+    "restoredToast": "Medición restaurada",
+    "restoreError": "Error al restaurar",
     "invalidValue": "Introduce un valor válido.",
     "invalidTimestamp": "Selecciona una fecha y hora válidas.",
     "loginRequired": "Inicia sesión para ver las mediciones.",
@@ -547,6 +551,9 @@
     "formResetConfirmAction": "Restablecer",
     "saveError": "Error al guardar",
     "deleteError": "Error al eliminar",
+    "deletedToast": "Entrada eliminada",
+    "restoredToast": "Entrada restaurada",
+    "restoreError": "Error al restaurar",
     "invalidTimestamp": "Selecciona una fecha y hora válidas.",
     "deleteConfirmTitle": "¿Eliminar entrada?",
     "deleteConfirmDescription": "Esta entrada de estado de ánimo se eliminará de forma permanente.",
@@ -806,6 +813,7 @@
       "loading": "Cargando…",
       "deleteCta": "Eliminar",
       "deleteConfirm": "¿Eliminar esta entrada?",
+      "deleteError": "No se pudo eliminar la entrada",
       "errorSeverity": "La gravedad debe estar entre 1 y 5",
       "errorEntry": "Elige un síntoma",
       "categories": {
@@ -1975,6 +1983,7 @@
       "errorBudget": "Has alcanzado el límite diario del coach. El cupo se reinicia a medianoche (UTC).",
       "errorProvider": "El coach no ha podido contactar con un proveedor de análisis ahora mismo. Inténtalo en un momento.",
       "errorNetwork": "Sin conexión a Internet — inténtalo de nuevo cuando vuelvas a estar en línea.",
+      "prefsSaveError": "No se pudieron guardar tus preferencias del Coach. Inténtalo de nuevo.",
       "errorCredentialExpired": "Tu conexión con el proveedor de IA ha caducado. Vuelve a conectarla en Ajustes para que el Coach siga funcionando.",
       "tagline": "Coach personal de salud, apoyado en tus datos.",
       "newChat": "Nueva conversación",
@@ -1995,6 +2004,7 @@
         "failed": "No se pudo añadir. Inténtalo de nuevo."
       },
       "selfContextChipDismiss": "Descartar pregunta",
+      "selfContextChipDismissError": "No se pudo descartar la pregunta",
       "voiceComingSoon": "La entrada por voz llega con la app de iOS en la v1.5.",
       "threadEmpty": "Pregúntame algo sobre tus tendencias, medicamentos o mediciones para empezar.",
       "historyTitle": "Conversaciones",
@@ -2083,6 +2093,7 @@
       "feedbackHelpful": "Útil",
       "feedbackUnhelpful": "Poco útil",
       "feedbackThanks": "Gracias por la indicación.",
+      "feedbackError": "No se pudo guardar el comentario",
       "dailyLimitTitle": "Límite diario alcanzado",
       "dailyLimitBody": "Límite diario alcanzado; reinicio a las 00:00 UTC.",
       "providerRateLimitTitle": "Proveedor con límite de tasa",
@@ -5641,6 +5652,8 @@
       "EMERGENCY": "Emergencia"
     },
     "loadError": "No se pudieron cargar tus datos del ciclo.",
+    "saveError": "No se pudo guardar tu registro del ciclo.",
+    "deleteError": "No se pudo eliminar la entrada.",
     "bbt": {
       "title": "Temperatura basal",
       "caption": "Tu temperatura matutina a lo largo de este ciclo. Una subida sostenida de unos 0,2 °C sigue a la ovulación.",
diff --git a/messages/fr.json b/messages/fr.json
index e739dc4c8..ea5d00ba2 100644
--- a/messages/fr.json
+++ b/messages/fr.json
@@ -3,6 +3,7 @@
     "save": "Enregistrer",
     "cancel": "Annuler",
     "delete": "Supprimer",
+    "undo": "Annuler",
     "edit": "Modifier",
     "moreOptions": "Plus d'options",
     "create": "Créer",
@@ -449,6 +450,9 @@
     "saveError": "Erreur lors de l’enregistrement",
     "duplicateTimestamp": "Une mesure de ce type existe déjà à cet horodatage.",
     "deleteError": "Erreur lors de la suppression",
+    "deletedToast": "Mesure supprimée",
+    "restoredToast": "Mesure restaurée",
+    "restoreError": "Échec de la restauration",
     "invalidValue": "Saisis une valeur valide.",
     "invalidTimestamp": "Choisis une date et une heure valides.",
     "loginRequired": "Connecte-toi pour voir tes mesures.",
@@ -547,6 +551,9 @@
     "formResetConfirmAction": "Réinitialiser",
     "saveError": "Erreur lors de l’enregistrement",
     "deleteError": "Erreur lors de la suppression",
+    "deletedToast": "Entrée supprimée",
+    "restoredToast": "Entrée restaurée",
+    "restoreError": "Échec de la restauration",
     "invalidTimestamp": "Choisis une date et une heure valides.",
     "deleteConfirmTitle": "Supprimer l’entrée ?",
     "deleteConfirmDescription": "Cette entrée d’humeur sera supprimée définitivement.",
@@ -806,6 +813,7 @@
       "loading": "Chargement…",
       "deleteCta": "Supprimer",
       "deleteConfirm": "Supprimer cette entrée ?",
+      "deleteError": "Impossible de supprimer l'entrée",
       "errorSeverity": "La sévérité doit être entre 1 et 5",
       "errorEntry": "Choisissez un symptôme",
       "categories": {
@@ -1975,6 +1983,7 @@
       "errorBudget": "Tu as atteint la limite quotidienne du coach. Le quota se réinitialise à minuit (UTC).",
       "errorProvider": "Le coach n’a pas pu joindre un fournisseur d’analyse maintenant. Réessaie dans un instant.",
       "errorNetwork": "Pas de connexion Internet — réessaie une fois reconnecté.",
+      "prefsSaveError": "Impossible d’enregistrer vos préférences du Coach. Réessayez.",
       "errorCredentialExpired": "Ta connexion au fournisseur d'IA a expiré. Reconnecte-la dans les Réglages pour que le Coach continue de fonctionner.",
       "tagline": "Coach personnel de santé, ancré sur tes données.",
       "newChat": "Nouvelle conversation",
@@ -1995,6 +2004,7 @@
         "failed": "Échec de l’ajout. Veuillez réessayer."
       },
       "selfContextChipDismiss": "Ignorer la question",
+      "selfContextChipDismissError": "Impossible de masquer la question",
       "voiceComingSoon": "La saisie vocale arrive avec l’app iOS en v1.5.",
       "threadEmpty": "Pose une question sur tes tendances, médicaments ou mesures pour démarrer.",
       "historyTitle": "Conversations",
@@ -2083,6 +2093,7 @@
       "feedbackHelpful": "Utile",
       "feedbackUnhelpful": "Peu utile",
       "feedbackThanks": "Merci pour l’indication.",
+      "feedbackError": "Impossible d'enregistrer le retour",
       "dailyLimitTitle": "Limite quotidienne atteinte",
       "dailyLimitBody": "Limite quotidienne atteinte ; réinitialisation à 00:00 UTC.",
       "providerRateLimitTitle": "Fournisseur limité en débit",
@@ -5641,6 +5652,8 @@
       "EMERGENCY": "Urgence"
     },
     "loadError": "Impossible de charger vos données de cycle.",
+    "saveError": "Impossible d’enregistrer votre saisie de cycle.",
+    "deleteError": "Impossible de supprimer l’entrée.",
     "bbt": {
       "title": "Température basale",
       "caption": "Votre température matinale sur ce cycle. Une hausse durable d'environ 0,2 °C suit l'ovulation.",
diff --git a/messages/it.json b/messages/it.json
index 3a37a3c38..d7bdb4689 100644
--- a/messages/it.json
+++ b/messages/it.json
@@ -3,6 +3,7 @@
     "save": "Salva",
     "cancel": "Annulla",
     "delete": "Elimina",
+    "undo": "Annulla",
     "edit": "Modifica",
     "moreOptions": "Altre opzioni",
     "create": "Crea",
@@ -449,6 +450,9 @@
     "saveError": "Errore durante il salvataggio",
     "duplicateTimestamp": "Esiste già una misurazione di questo tipo a questa marca temporale.",
     "deleteError": "Errore durante l’eliminazione",
+    "deletedToast": "Misurazione eliminata",
+    "restoredToast": "Misurazione ripristinata",
+    "restoreError": "Ripristino non riuscito",
     "invalidValue": "Inserisci un valore valido.",
     "invalidTimestamp": "Scegli una data e un’ora valide.",
     "loginRequired": "Accedi per vedere le misurazioni.",
@@ -547,6 +551,9 @@
     "formResetConfirmAction": "Reimposta",
     "saveError": "Errore durante il salvataggio",
     "deleteError": "Errore durante l’eliminazione",
+    "deletedToast": "Voce eliminata",
+    "restoredToast": "Voce ripristinata",
+    "restoreError": "Ripristino non riuscito",
     "invalidTimestamp": "Scegli una data e un’ora valide.",
     "deleteConfirmTitle": "Eliminare la voce?",
     "deleteConfirmDescription": "Questa voce dell’umore sarà eliminata in modo definitivo.",
@@ -806,6 +813,7 @@
       "loading": "Caricamento…",
       "deleteCta": "Elimina",
       "deleteConfirm": "Eliminare questa voce?",
+      "deleteError": "Impossibile eliminare la voce",
       "errorSeverity": "La gravità deve essere tra 1 e 5",
       "errorEntry": "Scegli un sintomo",
       "categories": {
@@ -1975,6 +1983,7 @@
       "errorBudget": "Hai raggiunto il limite giornaliero del coach. Il budget si reimposta a mezzanotte (UTC).",
       "errorProvider": "Il coach non è riuscito a contattare un provider di analisi ora. Riprova fra poco.",
       "errorNetwork": "Nessuna connessione Internet — riprova quando sei di nuovo online.",
+      "prefsSaveError": "Impossibile salvare le preferenze del Coach. Riprova.",
       "errorCredentialExpired": "La connessione al provider di IA è scaduta. Riconnettila nelle Impostazioni per mantenere attivo il Coach.",
       "tagline": "Coach personale di salute, basato sui tuoi dati.",
       "newChat": "Nuova chat",
@@ -1995,6 +2004,7 @@
         "failed": "Aggiunta non riuscita. Riprova."
       },
       "selfContextChipDismiss": "Ignora la domanda",
+      "selfContextChipDismissError": "Impossibile ignorare la domanda",
       "voiceComingSoon": "L’input vocale arriva con l’app iOS in v1.5.",
       "threadEmpty": "Chiedimi qualcosa sui tuoi trend, farmaci o misurazioni per iniziare.",
       "historyTitle": "Conversazioni",
@@ -2083,6 +2093,7 @@
       "feedbackHelpful": "Utile",
       "feedbackUnhelpful": "Poco utile",
       "feedbackThanks": "Grazie per il segnale.",
+      "feedbackError": "Impossibile salvare il feedback",
       "dailyLimitTitle": "Limite giornaliero raggiunto",
       "dailyLimitBody": "Limite giornaliero raggiunto; reset alle 00:00 UTC.",
       "providerRateLimitTitle": "Provider con rate-limit",
@@ -5641,6 +5652,8 @@
       "EMERGENCY": "Emergenza"
     },
     "loadError": "Impossibile caricare i dati del ciclo.",
+    "saveError": "Impossibile salvare la voce del ciclo.",
+    "deleteError": "Impossibile eliminare la voce.",
     "bbt": {
       "title": "Temperatura basale",
       "caption": "La tua temperatura mattutina in questo ciclo. Un rialzo prolungato di circa 0,2 °C segue l'ovulazione.",
diff --git a/messages/pl.json b/messages/pl.json
index 2b29de7e3..a64d238ab 100644
--- a/messages/pl.json
+++ b/messages/pl.json
@@ -3,6 +3,7 @@
     "save": "Zapisz",
     "cancel": "Anuluj",
     "delete": "Usuń",
+    "undo": "Cofnij",
     "edit": "Edytuj",
     "moreOptions": "Więcej opcji",
     "create": "Utwórz",
@@ -449,6 +450,9 @@
     "saveError": "Błąd zapisu",
     "duplicateTimestamp": "Pomiar tego typu już istnieje dla wybranej daty.",
     "deleteError": "Błąd usuwania",
+    "deletedToast": "Pomiar usunięty",
+    "restoredToast": "Pomiar przywrócony",
+    "restoreError": "Przywracanie nie powiodło się",
     "invalidValue": "Wprowadź poprawną wartość.",
     "invalidTimestamp": "Wybierz poprawną datę i godzinę.",
     "loginRequired": "Zaloguj się, aby zobaczyć pomiary.",
@@ -547,6 +551,9 @@
     "formResetConfirmAction": "Resetuj",
     "saveError": "Błąd zapisu",
     "deleteError": "Błąd usuwania",
+    "deletedToast": "Wpis usunięty",
+    "restoredToast": "Wpis przywrócony",
+    "restoreError": "Przywracanie nie powiodło się",
     "invalidTimestamp": "Wybierz poprawną datę i godzinę.",
     "deleteConfirmTitle": "Usunąć wpis?",
     "deleteConfirmDescription": "Ten wpis nastroju zostanie nieodwracalnie usunięty.",
@@ -806,6 +813,7 @@
       "loading": "Ładowanie…",
       "deleteCta": "Usuń",
       "deleteConfirm": "Usunąć ten wpis?",
+      "deleteError": "Nie udało się usunąć wpisu",
       "errorSeverity": "Nasilenie musi mieścić się w zakresie 1–5",
       "errorEntry": "Wybierz objaw",
       "categories": {
@@ -1975,6 +1983,7 @@
       "errorBudget": "Osiągnięto dzienny limit coacha. Limit resetuje się o północy (UTC).",
       "errorProvider": "Coach nie mógł teraz skontaktować się z dostawcą analizy. Spróbuj za chwilę.",
       "errorNetwork": "Brak połączenia z Internetem — spróbuj ponownie, gdy wrócisz online.",
+      "prefsSaveError": "Nie udało się zapisać ustawień Coacha. Spróbuj ponownie.",
       "errorCredentialExpired": "Połączenie z dostawcą AI wygasło. Połącz je ponownie w Ustawieniach, aby Coach działał dalej.",
       "tagline": "Osobisty coach zdrowia, oparty na twoich danych.",
       "newChat": "Nowa rozmowa",
@@ -1995,6 +2004,7 @@
         "failed": "Nie udało się dodać. Spróbuj ponownie."
       },
       "selfContextChipDismiss": "Odrzuć pytanie",
+      "selfContextChipDismissError": "Nie udało się odrzucić pytania",
       "voiceComingSoon": "Wejście głosowe pojawi się z aplikacją iOS w v1.5.",
       "threadEmpty": "Zapytaj o swoje trendy, leki lub pomiary, aby zacząć.",
       "historyTitle": "Rozmowy",
@@ -2083,6 +2093,7 @@
       "feedbackHelpful": "Przydatne",
       "feedbackUnhelpful": "Mało przydatne",
       "feedbackThanks": "Dzięki za sygnał.",
+      "feedbackError": "Nie udało się zapisać opinii",
       "dailyLimitTitle": "Osiągnięto dzienny limit",
       "dailyLimitBody": "Osiągnięto dzienny limit; reset o 00:00 UTC.",
       "providerRateLimitTitle": "Dostawca z ograniczeniem",
@@ -5641,6 +5652,8 @@
       "EMERGENCY": "Awaryjna"
     },
     "loadError": "Nie udało się wczytać danych cyklu.",
+    "saveError": "Nie udało się zapisać wpisu cyklu.",
+    "deleteError": "Nie udało się usunąć wpisu.",
     "bbt": {
       "title": "Podstawowa temperatura ciała",
       "caption": "Twoja poranna temperatura w tym cyklu. Trwały wzrost o około 0,2 °C następuje po owulacji.",
diff --git a/src/app/__tests__/dashboard-analytics-split.test.ts b/src/app/__tests__/dashboard-analytics-split.test.ts
index 227fb7b42..5ddaa2115 100644
--- a/src/app/__tests__/dashboard-analytics-split.test.ts
+++ b/src/app/__tests__/dashboard-analytics-split.test.ts
@@ -9,7 +9,7 @@ import { join } from "node:path";
  * thick `/api/analytics` envelope; every per-type tile waited on the
  * heavy fan-out before paint. Mood and medication tiles arrived first
  * (separate routes) and then every other tile arrived as one burst,
- * which Marc reported as "etwas nervig" in the v1.4.39.1 post-deploy
+ * which the maintainer reported as "etwas nervig" in the v1.4.39.1 post-deploy
  * trace.
  *
  * Post-fix the dashboard mounts TWO `useAnalyticsQuery` calls in
diff --git a/src/app/api/admin/audit-log/__tests__/route.test.ts b/src/app/api/admin/audit-log/__tests__/route.test.ts
index 14ad22f0e..600ee91ff 100644
--- a/src/app/api/admin/audit-log/__tests__/route.test.ts
+++ b/src/app/api/admin/audit-log/__tests__/route.test.ts
@@ -70,19 +70,19 @@ describe("GET /api/admin/audit-log — extended filters", () => {
   });
 
   it("filters by `actor` against userId OR user.username", async () => {
-    await GET(req("actor=marc"));
+    await GET(req("actor=testuser"));
     const call = vi.mocked(prisma.auditLog.findMany).mock.calls[0][0]!;
     const where = call.where as Record<string, unknown>;
     // Expect an OR clause covering userId + user.username (contains)
     expect(where.OR).toBeDefined();
     const or = where.OR as Array<Record<string, unknown>>;
-    const matchesUserId = or.some((c) => c.userId === "marc");
+    const matchesUserId = or.some((c) => c.userId === "testuser");
     const matchesUsername = or.some(
       (c) =>
         typeof c.user === "object" &&
         c.user !== null &&
-        // user: { username: { contains: "marc", mode: "insensitive" } }
-        JSON.stringify(c).toLowerCase().includes("marc"),
+        // user: { username: { contains: "testuser", mode: "insensitive" } }
+        JSON.stringify(c).toLowerCase().includes("testuser"),
     );
     expect(matchesUserId).toBe(true);
     expect(matchesUsername).toBe(true);
diff --git a/src/app/api/admin/import-apple-health-export/__tests__/route.test.ts b/src/app/api/admin/import-apple-health-export/__tests__/route.test.ts
index 40531c298..16ef30c14 100644
--- a/src/app/api/admin/import-apple-health-export/__tests__/route.test.ts
+++ b/src/app/api/admin/import-apple-health-export/__tests__/route.test.ts
@@ -60,7 +60,7 @@ import { getSession } from "@/lib/auth/session";
 
 const ADMIN_SESSION = {
   session: { id: "sess-admin", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "admin-1", username: "marc", role: "ADMIN" as const },
+  user: { id: "admin-1", username: "testuser", role: "ADMIN" as const },
 };
 const USER_SESSION = {
   session: { id: "sess-user", expiresAt: new Date(Date.now() + 3_600_000) },
diff --git a/src/app/api/admin/notifications/reminder-check/route.ts b/src/app/api/admin/notifications/reminder-check/route.ts
index 56ebabcfb..784b7d4dd 100644
--- a/src/app/api/admin/notifications/reminder-check/route.ts
+++ b/src/app/api/admin/notifications/reminder-check/route.ts
@@ -4,7 +4,7 @@ import { annotate, getEvent } from "@/lib/logging/context";
 import { apiSuccess } from "@/lib/api-response";
 import { parseScheduleRecurrence } from "@/lib/medication-schedule";
 import { dispatchLocalisedNotification } from "@/lib/notifications/dispatch-localised";
-import { getUserTodayBounds, getDayOfWeekInTz } from "@/lib/timezone";
+import { getUserTodayBounds, getDayOfWeekInTz } from "@/lib/tz/local-day";
 
 export const dynamic = "force-dynamic";
 
diff --git a/src/app/api/admin/settings/assistant-flags/__tests__/route.test.ts b/src/app/api/admin/settings/assistant-flags/__tests__/route.test.ts
index 46dcce451..99fd498e0 100644
--- a/src/app/api/admin/settings/assistant-flags/__tests__/route.test.ts
+++ b/src/app/api/admin/settings/assistant-flags/__tests__/route.test.ts
@@ -33,7 +33,7 @@ import { prisma } from "@/lib/db";
 
 const ADMIN_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "admin-1", username: "marc", role: "ADMIN" as const },
+  user: { id: "admin-1", username: "testuser", role: "ADMIN" as const },
 };
 const USER_OK = {
   session: { id: "sess-2", expiresAt: new Date(Date.now() + 3_600_000) },
diff --git a/src/app/api/admin/users/[id]/__tests__/route.test.ts b/src/app/api/admin/users/[id]/__tests__/route.test.ts
index 8d7324216..07b540371 100644
--- a/src/app/api/admin/users/[id]/__tests__/route.test.ts
+++ b/src/app/api/admin/users/[id]/__tests__/route.test.ts
@@ -71,7 +71,7 @@ describe("PUT /api/admin/users/[id]", () => {
       new HttpError(401, "Not authenticated"),
     );
     await expect(
-      PUT(jsonReq({ username: "marc" }), params("u1")),
+      PUT(jsonReq({ username: "testuser" }), params("u1")),
     ).rejects.toThrow("Not authenticated");
   });
 
@@ -80,7 +80,7 @@ describe("PUT /api/admin/users/[id]", () => {
       new HttpError(403, "Admin access required"),
     );
     await expect(
-      PUT(jsonReq({ username: "marc" }), params("u1")),
+      PUT(jsonReq({ username: "testuser" }), params("u1")),
     ).rejects.toThrow("Admin access required");
   });
 
@@ -97,7 +97,7 @@ describe("PUT /api/admin/users/[id]", () => {
 
   it("returns 404 when target user does not exist", async () => {
     vi.mocked(prisma.user.findUnique).mockResolvedValue(null);
-    const res = await PUT(jsonReq({ username: "marc" }), params("u-missing"));
+    const res = await PUT(jsonReq({ username: "testuser" }), params("u-missing"));
     expect(res.status).toBe(404);
     expect(vi.mocked(prisma.user.update)).not.toHaveBeenCalled();
   });
diff --git a/src/app/api/auth/check-user/__tests__/route.test.ts b/src/app/api/auth/check-user/__tests__/route.test.ts
index 9c1a71389..660ee1abf 100644
--- a/src/app/api/auth/check-user/__tests__/route.test.ts
+++ b/src/app/api/auth/check-user/__tests__/route.test.ts
@@ -102,7 +102,7 @@ describe("POST /api/auth/check-user — audit-log row (M-1)", () => {
       _count: { passkeys: 2 },
     } as never);
 
-    const res = await POST(makeRequest({ identifier: "marc" }));
+    const res = await POST(makeRequest({ identifier: "testuser" }));
     expect(res.status).toBe(200);
 
     expect(auditLog).toHaveBeenCalledTimes(1);
@@ -111,7 +111,7 @@ describe("POST /api/auth/check-user — audit-log row (M-1)", () => {
       ipAddress: "203.0.113.1",
       details: {
         branch: "passkey_only",
-        identifier_hash: expectedHash("marc"),
+        identifier_hash: expectedHash("testuser"),
       },
     });
   });
@@ -123,13 +123,13 @@ describe("POST /api/auth/check-user — audit-log row (M-1)", () => {
       _count: { passkeys: 0 },
     } as never);
 
-    const res = await POST(makeRequest({ identifier: "marc@example.com" }));
+    const res = await POST(makeRequest({ identifier: "user@example.com" }));
     expect(res.status).toBe(200);
 
     const args = vi.mocked(auditLog).mock.calls[0];
     expect(args[1]?.details).toEqual({
       branch: "email_fallback",
-      identifier_hash: expectedHash("marc@example.com"),
+      identifier_hash: expectedHash("user@example.com"),
     });
     expect(args[1]?.userId).toBe("user-2");
   });
diff --git a/src/app/api/auth/login/__tests__/native-token.test.ts b/src/app/api/auth/login/__tests__/native-token.test.ts
index 3b71d3e9f..6661fe644 100644
--- a/src/app/api/auth/login/__tests__/native-token.test.ts
+++ b/src/app/api/auth/login/__tests__/native-token.test.ts
@@ -75,8 +75,8 @@ import { createSession } from "@/lib/auth/session";
 
 const FAKE_USER = {
   id: "user-1",
-  username: "marc",
-  email: "marc@example.com",
+  username: "testuser",
+  email: "user@example.com",
   passwordHash: "$argon2id$...",
 };
 
@@ -88,7 +88,7 @@ function makeRequest(headers: Record<string, string> = {}): NextRequest {
       ...headers,
     },
     body: JSON.stringify({
-      email: "marc@example.com",
+      email: "user@example.com",
       password: "supersecret",
     }),
   });
diff --git a/src/app/api/auth/me/devices/[id]/__tests__/route.test.ts b/src/app/api/auth/me/devices/[id]/__tests__/route.test.ts
index 4fc0c415f..c0cf0b4c9 100644
--- a/src/app/api/auth/me/devices/[id]/__tests__/route.test.ts
+++ b/src/app/api/auth/me/devices/[id]/__tests__/route.test.ts
@@ -48,7 +48,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(): NextRequest {
diff --git a/src/app/api/auth/me/devices/__tests__/route.test.ts b/src/app/api/auth/me/devices/__tests__/route.test.ts
index c1d6460ea..6143b8f07 100644
--- a/src/app/api/auth/me/devices/__tests__/route.test.ts
+++ b/src/app/api/auth/me/devices/__tests__/route.test.ts
@@ -35,7 +35,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(deviceIdHeader?: string): NextRequest {
diff --git a/src/app/api/auth/me/disable-coach/__tests__/route.test.ts b/src/app/api/auth/me/disable-coach/__tests__/route.test.ts
index 8b71b1547..71e2cbe9d 100644
--- a/src/app/api/auth/me/disable-coach/__tests__/route.test.ts
+++ b/src/app/api/auth/me/disable-coach/__tests__/route.test.ts
@@ -47,7 +47,7 @@ import { checkRateLimit } from "@/lib/rate-limit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function mkPatch(body: unknown): Request {
diff --git a/src/app/api/auth/me/doctor-report-prefs/__tests__/route.test.ts b/src/app/api/auth/me/doctor-report-prefs/__tests__/route.test.ts
index 85722cba5..4550fc90c 100644
--- a/src/app/api/auth/me/doctor-report-prefs/__tests__/route.test.ts
+++ b/src/app/api/auth/me/doctor-report-prefs/__tests__/route.test.ts
@@ -39,7 +39,7 @@ import { DEFAULT_DOCTOR_REPORT_PREFS } from "@/lib/validations/doctor-report-pre
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function mkPut(body: unknown): Request {
@@ -69,7 +69,7 @@ describe("GET /api/auth/me/doctor-report-prefs", () => {
       data: typeof DEFAULT_DOCTOR_REPORT_PREFS;
     };
     expect(env.data).toEqual(DEFAULT_DOCTOR_REPORT_PREFS);
-    expect(env.data.mood).toBe(false); // privacy default per Marc
+    expect(env.data.mood).toBe(false); // privacy default per the maintainer
   });
 });
 
@@ -145,7 +145,7 @@ describe("PUT /api/auth/me/doctor-report-prefs", () => {
   });
 
   // ── Case 4 — unauthenticated cross-user request ────────────────────
-  // Marc's spec mentions "cross-user 404" — the route layer returns 401
+  // the maintainer's spec mentions "cross-user 404" — the route layer returns 401
   // when there is no session at all, which is the only "you are not the
   // right user" surface available before requireAuth() resolves an
   // identity. `prisma.user.update` must NOT fire in this case.
diff --git a/src/app/api/auth/me/notification-prefs/__tests__/route.test.ts b/src/app/api/auth/me/notification-prefs/__tests__/route.test.ts
index 3e8d598b9..8632c2e7d 100644
--- a/src/app/api/auth/me/notification-prefs/__tests__/route.test.ts
+++ b/src/app/api/auth/me/notification-prefs/__tests__/route.test.ts
@@ -48,7 +48,7 @@ import { checkRateLimit } from "@/lib/rate-limit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function mkPatch(body: unknown): Request {
diff --git a/src/app/api/auth/me/research-mode/__tests__/route.test.ts b/src/app/api/auth/me/research-mode/__tests__/route.test.ts
index 4de7c44ca..0f57c8316 100644
--- a/src/app/api/auth/me/research-mode/__tests__/route.test.ts
+++ b/src/app/api/auth/me/research-mode/__tests__/route.test.ts
@@ -48,7 +48,7 @@ import { RESEARCH_MODE_DISCLAIMER_VERSION } from "@/lib/medications/glp1-pk";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function mkPost(body: unknown): Request {
diff --git a/src/app/api/auth/me/source-priority/__tests__/route.test.ts b/src/app/api/auth/me/source-priority/__tests__/route.test.ts
index fa1980baa..fdc7cc849 100644
--- a/src/app/api/auth/me/source-priority/__tests__/route.test.ts
+++ b/src/app/api/auth/me/source-priority/__tests__/route.test.ts
@@ -37,7 +37,7 @@ import { auditLog } from "@/lib/auth/audit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function mkPut(body: unknown): Request {
diff --git a/src/app/api/auth/me/timezone/__tests__/route.test.ts b/src/app/api/auth/me/timezone/__tests__/route.test.ts
index 68501467f..c8b42b530 100644
--- a/src/app/api/auth/me/timezone/__tests__/route.test.ts
+++ b/src/app/api/auth/me/timezone/__tests__/route.test.ts
@@ -38,7 +38,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function mkReq(body: unknown): NextRequest {
diff --git a/src/app/api/auth/me/unit-preference/__tests__/route.test.ts b/src/app/api/auth/me/unit-preference/__tests__/route.test.ts
index 86925d8e1..8bd6b0f25 100644
--- a/src/app/api/auth/me/unit-preference/__tests__/route.test.ts
+++ b/src/app/api/auth/me/unit-preference/__tests__/route.test.ts
@@ -46,7 +46,7 @@ import { auditLog } from "@/lib/auth/audit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function mkPatch(body: unknown): Request {
diff --git a/src/app/api/auth/passkey/login-verify/__tests__/native-token.test.ts b/src/app/api/auth/passkey/login-verify/__tests__/native-token.test.ts
index 18fad6ff4..dd8b27419 100644
--- a/src/app/api/auth/passkey/login-verify/__tests__/native-token.test.ts
+++ b/src/app/api/auth/passkey/login-verify/__tests__/native-token.test.ts
@@ -60,8 +60,8 @@ import {
 
 const FAKE_USER = {
   id: "user-1",
-  username: "marc",
-  email: "marc@example.com",
+  username: "testuser",
+  email: "user@example.com",
 };
 
 function makeRequest(headers: Record<string, string> = {}): NextRequest {
diff --git a/src/app/api/consent/ai/__tests__/route.test.ts b/src/app/api/consent/ai/__tests__/route.test.ts
index 4b9831a1e..dfe3c312e 100644
--- a/src/app/api/consent/ai/__tests__/route.test.ts
+++ b/src/app/api/consent/ai/__tests__/route.test.ts
@@ -41,7 +41,7 @@ import { auditLog } from "@/lib/auth/audit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(body: unknown): NextRequest {
diff --git a/src/app/api/consent/ai/latest/__tests__/route.test.ts b/src/app/api/consent/ai/latest/__tests__/route.test.ts
index d608863c9..67bea48bf 100644
--- a/src/app/api/consent/ai/latest/__tests__/route.test.ts
+++ b/src/app/api/consent/ai/latest/__tests__/route.test.ts
@@ -41,7 +41,7 @@ import { auditLog } from "@/lib/auth/audit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/dashboard/summary/__tests__/route.test.ts b/src/app/api/dashboard/summary/__tests__/route.test.ts
index 82b75acae..11a8c39db 100644
--- a/src/app/api/dashboard/summary/__tests__/route.test.ts
+++ b/src/app/api/dashboard/summary/__tests__/route.test.ts
@@ -65,7 +65,7 @@ const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
   user: {
     id: "user-1",
-    username: "marc",
+    username: "testuser",
     role: "USER" as const,
     displayName: null,
   },
@@ -134,7 +134,7 @@ describe("GET /api/dashboard/summary", () => {
         metrics: Array<{ id: string; kind: string; sparkline: number[] }>;
       };
     };
-    expect(body.data.greeting.salutation).toBe("Hi, marc");
+    expect(body.data.greeting.salutation).toBe("Hi, testuser");
     expect(body.data.streak.currentDays).toBe(0);
     expect(body.data.compliance.scheduledToday).toBe(0);
     // REG-11 (v1.4.44): weight is the only always-emitted base metric.
diff --git a/src/app/api/devices/[id]/__tests__/route.test.ts b/src/app/api/devices/[id]/__tests__/route.test.ts
index a296926ab..5c9d696f7 100644
--- a/src/app/api/devices/[id]/__tests__/route.test.ts
+++ b/src/app/api/devices/[id]/__tests__/route.test.ts
@@ -48,7 +48,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(): NextRequest {
diff --git a/src/app/api/devices/__tests__/route.test.ts b/src/app/api/devices/__tests__/route.test.ts
index cf3136fe2..5b76b5850 100644
--- a/src/app/api/devices/__tests__/route.test.ts
+++ b/src/app/api/devices/__tests__/route.test.ts
@@ -59,7 +59,7 @@ import { checkRateLimit } from "@/lib/rate-limit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(body: unknown): NextRequest {
diff --git a/src/app/api/doctor-report/__tests__/pdf-route.test.ts b/src/app/api/doctor-report/__tests__/pdf-route.test.ts
index 37a83ba9f..976b297da 100644
--- a/src/app/api/doctor-report/__tests__/pdf-route.test.ts
+++ b/src/app/api/doctor-report/__tests__/pdf-route.test.ts
@@ -72,7 +72,7 @@ function setEmptyDataMocks() {
   );
   vi.mocked(prisma.moodEntry.findMany).mockResolvedValue([] as never);
   vi.mocked(prisma.user.findUnique).mockResolvedValue({
-    username: "marc",
+    username: "testuser",
     dateOfBirth: null,
     gender: null,
     heightCm: null,
diff --git a/src/app/api/doctor-report/availability/route.ts b/src/app/api/doctor-report/availability/route.ts
index e2a818a95..209f04966 100644
--- a/src/app/api/doctor-report/availability/route.ts
+++ b/src/app/api/doctor-report/availability/route.ts
@@ -3,7 +3,7 @@
  *
  * Returns one boolean per toggleable section so the dialog can hide
  * checkboxes for data types that have zero rows in the user-selected
- * date range (Marc's "hide-when-empty" rule). Pure presence check —
+ * date range (the maintainer's "hide-when-empty" rule). Pure presence check —
  * `count` queries on small indexed tables — so this is cheap enough to
  * run on every date-range change in the dialog without driving cost.
  *
diff --git a/src/app/api/feature-flags/__tests__/route.test.ts b/src/app/api/feature-flags/__tests__/route.test.ts
index 1d0b27b35..0bd8c9e44 100644
--- a/src/app/api/feature-flags/__tests__/route.test.ts
+++ b/src/app/api/feature-flags/__tests__/route.test.ts
@@ -36,7 +36,7 @@ import { prisma } from "@/lib/db";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(): NextRequest {
diff --git a/src/app/api/gamification/achievements/__tests__/hidden-redaction.test.ts b/src/app/api/gamification/achievements/__tests__/hidden-redaction.test.ts
index db16bbcd9..69d8ad58e 100644
--- a/src/app/api/gamification/achievements/__tests__/hidden-redaction.test.ts
+++ b/src/app/api/gamification/achievements/__tests__/hidden-redaction.test.ts
@@ -43,7 +43,7 @@ const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
   user: {
     id: "user-1",
-    username: "marc",
+    username: "testuser",
     role: "USER" as const,
     createdAt: new Date("2026-03-01T00:00:00.000Z"),
     heightCm: null,
diff --git a/src/app/api/gamification/achievements/__tests__/ios-format.test.ts b/src/app/api/gamification/achievements/__tests__/ios-format.test.ts
index 8caf04752..9d46e416f 100644
--- a/src/app/api/gamification/achievements/__tests__/ios-format.test.ts
+++ b/src/app/api/gamification/achievements/__tests__/ios-format.test.ts
@@ -43,7 +43,7 @@ const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
   user: {
     id: "user-1",
-    username: "marc",
+    username: "testuser",
     role: "USER" as const,
     createdAt: new Date("2026-03-01T00:00:00.000Z"),
     heightCm: null,
diff --git a/src/app/api/import/apple-health-export/[jobId]/status/__tests__/route.test.ts b/src/app/api/import/apple-health-export/[jobId]/status/__tests__/route.test.ts
index 35badf1eb..08fda943d 100644
--- a/src/app/api/import/apple-health-export/[jobId]/status/__tests__/route.test.ts
+++ b/src/app/api/import/apple-health-export/[jobId]/status/__tests__/route.test.ts
@@ -37,7 +37,7 @@ import { getSession } from "@/lib/auth/session";
 
 const OWNER_SESSION = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 const OTHER_SESSION = {
   session: { id: "sess-2", expiresAt: new Date(Date.now() + 3_600_000) },
@@ -45,7 +45,7 @@ const OTHER_SESSION = {
 };
 const ADMIN_SESSION = {
   session: { id: "sess-a", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "admin-1", username: "marc-admin", role: "ADMIN" as const },
+  user: { id: "admin-1", username: "test-admin", role: "ADMIN" as const },
 };
 
 const NOW = new Date("2026-05-15T10:00:00.000Z");
diff --git a/src/app/api/import/apple-health-export/__tests__/route.test.ts b/src/app/api/import/apple-health-export/__tests__/route.test.ts
index f6613f3a3..fa4be13bf 100644
--- a/src/app/api/import/apple-health-export/__tests__/route.test.ts
+++ b/src/app/api/import/apple-health-export/__tests__/route.test.ts
@@ -58,7 +58,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/insights/blood-pressure-status/__tests__/route.test.ts b/src/app/api/insights/blood-pressure-status/__tests__/route.test.ts
index 44d04cb2c..8c56d6382 100644
--- a/src/app/api/insights/blood-pressure-status/__tests__/route.test.ts
+++ b/src/app/api/insights/blood-pressure-status/__tests__/route.test.ts
@@ -45,7 +45,7 @@ import { prisma } from "@/lib/db";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const, locale: "en" },
+  user: { id: "user-1", username: "testuser", role: "USER" as const, locale: "en" },
 };
 
 const callGet = GET as unknown as (req: NextRequest) => Promise<Response>;
diff --git a/src/app/api/insights/cards/__tests__/route.test.ts b/src/app/api/insights/cards/__tests__/route.test.ts
index 054ea6182..0f6b2abd0 100644
--- a/src/app/api/insights/cards/__tests__/route.test.ts
+++ b/src/app/api/insights/cards/__tests__/route.test.ts
@@ -41,7 +41,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/insights/comprehensive/__tests__/route.test.ts b/src/app/api/insights/comprehensive/__tests__/route.test.ts
index c9f7d5033..024383604 100644
--- a/src/app/api/insights/comprehensive/__tests__/route.test.ts
+++ b/src/app/api/insights/comprehensive/__tests__/route.test.ts
@@ -97,7 +97,7 @@ const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
   user: {
     id: "user-comp-1",
-    username: "marc",
+    username: "testuser",
     role: "USER" as const,
     locale: "en",
   },
diff --git a/src/app/api/insights/correlations/__tests__/route.test.ts b/src/app/api/insights/correlations/__tests__/route.test.ts
index 9933d4ec1..3899fa947 100644
--- a/src/app/api/insights/correlations/__tests__/route.test.ts
+++ b/src/app/api/insights/correlations/__tests__/route.test.ts
@@ -45,7 +45,7 @@ import { checkAnalyticsReadRateLimit } from "@/lib/rate-limit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/insights/correlations/route.ts b/src/app/api/insights/correlations/route.ts
index eae72346b..c7b1513cb 100644
--- a/src/app/api/insights/correlations/route.ts
+++ b/src/app/api/insights/correlations/route.ts
@@ -21,7 +21,7 @@ import { annotate } from "@/lib/logging/context";
 import { checkAnalyticsReadRateLimit } from "@/lib/rate-limit";
 import { requireAssistantSurface } from "@/lib/feature-flags";
 import { prisma } from "@/lib/db";
-import { getLocalDateParts } from "@/lib/timezone";
+import { wallClockInTz } from "@/lib/tz/wall-clock";
 import type { MeasurementType } from "@/generated/prisma/client";
 import {
   discoverCorrelations,
@@ -39,7 +39,7 @@ const WINDOW_DAYS = 180;
 
 /** Day key (YYYY-MM-DD) for an instant in the user's display timezone. */
 function tzDayKey(at: Date, tz: string): string {
-  const { year, month, day } = getLocalDateParts(at, tz);
+  const { year, month, day } = wallClockInTz(at, tz);
   const mm = String(month).padStart(2, "0");
   const dd = String(day).padStart(2, "0");
   return `${year}-${mm}-${dd}`;
diff --git a/src/app/api/insights/derived/__tests__/route.test.ts b/src/app/api/insights/derived/__tests__/route.test.ts
index fca913f30..f6f8802a1 100644
--- a/src/app/api/insights/derived/__tests__/route.test.ts
+++ b/src/app/api/insights/derived/__tests__/route.test.ts
@@ -64,7 +64,7 @@ import { computeDerivedMetric } from "@/lib/insights/derived";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const, locale: "en" },
+  user: { id: "user-1", username: "testuser", role: "USER" as const, locale: "en" },
 };
 
 const callGet = GET as unknown as (req: NextRequest) => Promise<Response>;
diff --git a/src/app/api/insights/derived/batch/__tests__/route.test.ts b/src/app/api/insights/derived/batch/__tests__/route.test.ts
index 58992b16f..96f550009 100644
--- a/src/app/api/insights/derived/batch/__tests__/route.test.ts
+++ b/src/app/api/insights/derived/batch/__tests__/route.test.ts
@@ -54,7 +54,7 @@ import { computeDerivedMetric } from "@/lib/insights/derived";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const, locale: "en" },
+  user: { id: "user-1", username: "testuser", role: "USER" as const, locale: "en" },
 };
 
 const callGet = GET as unknown as (req: NextRequest) => Promise<Response>;
diff --git a/src/app/api/insights/generate/__tests__/route.test.ts b/src/app/api/insights/generate/__tests__/route.test.ts
index 41f147185..2536a1e76 100644
--- a/src/app/api/insights/generate/__tests__/route.test.ts
+++ b/src/app/api/insights/generate/__tests__/route.test.ts
@@ -268,7 +268,7 @@ describe("POST /api/insights/generate — provider error mapping", () => {
 });
 
 // v1.4.16 A7.1: rate limit raised from 2 → 10/h, env-configurable.
-// the maintainer reported the previous 2/h was too aggressive when iterating on
+// The maintainer reported the previous 2/h was too aggressive when iterating on
 // settings. The 10/h ceiling is the new default; the env override lets
 // operators on a tight LLM budget dial it back without a rebuild.
 describe("POST /api/insights/generate — rate limit (v1.4.16 A7.1)", () => {
diff --git a/src/app/api/insights/metric-status/__tests__/route.test.ts b/src/app/api/insights/metric-status/__tests__/route.test.ts
index 45626b4a1..37aab757f 100644
--- a/src/app/api/insights/metric-status/__tests__/route.test.ts
+++ b/src/app/api/insights/metric-status/__tests__/route.test.ts
@@ -47,7 +47,7 @@ import { generateMetricStatus } from "@/lib/insights/metric-status";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const, locale: "en" },
+  user: { id: "user-1", username: "testuser", role: "USER" as const, locale: "en" },
 };
 
 const callGet = GET as unknown as (req: NextRequest) => Promise<Response>;
diff --git a/src/app/api/insights/pregenerate/__tests__/route.test.ts b/src/app/api/insights/pregenerate/__tests__/route.test.ts
index 9b9cdb332..a4852bc19 100644
--- a/src/app/api/insights/pregenerate/__tests__/route.test.ts
+++ b/src/app/api/insights/pregenerate/__tests__/route.test.ts
@@ -46,7 +46,7 @@ import { enqueueForceWarm } from "@/lib/jobs/insight-pregenerate-shared";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const, locale: "en" },
+  user: { id: "user-1", username: "testuser", role: "USER" as const, locale: "en" },
 };
 
 const callPost = POST as unknown as (req: NextRequest) => Promise<Response>;
diff --git a/src/app/api/insights/rhythm-events/__tests__/route.test.ts b/src/app/api/insights/rhythm-events/__tests__/route.test.ts
index a94647a50..fbc29ca93 100644
--- a/src/app/api/insights/rhythm-events/__tests__/route.test.ts
+++ b/src/app/api/insights/rhythm-events/__tests__/route.test.ts
@@ -41,7 +41,7 @@ import { prisma } from "@/lib/db";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const, locale: "en" },
+  user: { id: "user-1", username: "testuser", role: "USER" as const, locale: "en" },
 };
 
 const callGet = GET as unknown as (req: NextRequest) => Promise<Response>;
diff --git a/src/app/api/insights/targets/__tests__/route.test.ts b/src/app/api/insights/targets/__tests__/route.test.ts
index 47ea4f4aa..b413e80a0 100644
--- a/src/app/api/insights/targets/__tests__/route.test.ts
+++ b/src/app/api/insights/targets/__tests__/route.test.ts
@@ -85,7 +85,7 @@ import { __resetAllCachesForTests } from "@/lib/cache/server-cache";
 
 const SESSION_USER = {
   id: "user-targets-1",
-  username: "marc",
+  username: "testuser",
   role: "USER" as const,
   timezone: "Europe/Berlin",
   heightCm: 180,
diff --git a/src/app/api/integrations/healthkit/__tests__/route.test.ts b/src/app/api/integrations/healthkit/__tests__/route.test.ts
index faee976e1..91df8f408 100644
--- a/src/app/api/integrations/healthkit/__tests__/route.test.ts
+++ b/src/app/api/integrations/healthkit/__tests__/route.test.ts
@@ -37,7 +37,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/measurement-categories/__tests__/route.test.ts b/src/app/api/measurement-categories/__tests__/route.test.ts
index dc99bb6c6..6db396ff7 100644
--- a/src/app/api/measurement-categories/__tests__/route.test.ts
+++ b/src/app/api/measurement-categories/__tests__/route.test.ts
@@ -28,7 +28,7 @@ import { MEASUREMENT_CATEGORIES } from "@/lib/measurements/categories";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(): NextRequest {
diff --git a/src/app/api/measurements/__tests__/put-duplicate-timestamp.test.ts b/src/app/api/measurements/__tests__/put-duplicate-timestamp.test.ts
index f7679aa90..db6645dce 100644
--- a/src/app/api/measurements/__tests__/put-duplicate-timestamp.test.ts
+++ b/src/app/api/measurements/__tests__/put-duplicate-timestamp.test.ts
@@ -36,7 +36,7 @@ import { Prisma } from "@/generated/prisma/client";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function putRequest(id: string, body: Record<string, unknown>): NextRequest {
diff --git a/src/app/api/measurements/__tests__/range-aggregation-route.test.ts b/src/app/api/measurements/__tests__/range-aggregation-route.test.ts
index 6f92b73eb..75da4312a 100644
--- a/src/app/api/measurements/__tests__/range-aggregation-route.test.ts
+++ b/src/app/api/measurements/__tests__/range-aggregation-route.test.ts
@@ -350,7 +350,7 @@ describe("GET /api/measurements — all-time semantics (SD-H1)", () => {
   });
 
   it("source=rollup folds the partition inline and re-reads when the rollup is under-converged (v1.4.39.2)", async () => {
-    // Marc's pre-fix production trace: 30-day BP_SYS window returned
+    // The maintainer's pre-fix production trace: 30-day BP_SYS window returned
     // `total: 2` from the rollup branch even though `measurements`
     // carried ~30 distinct days. The chart tripped its `< 3 daily
     // points` empty-state because the route short-circuited on
diff --git a/src/app/api/measurements/batch/__tests__/pr-detection-hook.test.ts b/src/app/api/measurements/batch/__tests__/pr-detection-hook.test.ts
index 483fc376d..cdfd65560 100644
--- a/src/app/api/measurements/batch/__tests__/pr-detection-hook.test.ts
+++ b/src/app/api/measurements/batch/__tests__/pr-detection-hook.test.ts
@@ -60,7 +60,7 @@ import { enqueuePrDetection } from "@/lib/jobs/pr-detection";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function makeRequest(body: unknown): NextRequest {
diff --git a/src/app/api/measurements/restore/__tests__/route.test.ts b/src/app/api/measurements/restore/__tests__/route.test.ts
new file mode 100644
index 000000000..e1e6747f7
--- /dev/null
+++ b/src/app/api/measurements/restore/__tests__/route.test.ts
@@ -0,0 +1,177 @@
+/**
+ * v1.16.4 — POST /api/measurements/restore.
+ *
+ * Asserts the ownership-scoped un-tombstone contract that backs the
+ * delete-Undo toast: only owned, currently-tombstoned rows are touched;
+ * a forged / foreign / never-deleted id is a silent no-op (no 404
+ * existence leak); the rollup recompute collapses to the unique
+ * `(type, day)` set; the >200-id cap returns 422.
+ */
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { NextRequest } from "next/server";
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    measurement: {
+      findMany: vi.fn(),
+      updateMany: vi.fn(),
+    },
+    auditLog: { create: vi.fn() },
+  },
+}));
+
+vi.mock("@/lib/auth/session", () => ({ getSession: vi.fn() }));
+vi.mock("@/lib/auth/audit", () => ({
+  auditLog: vi.fn().mockResolvedValue(undefined),
+}));
+vi.mock("@/lib/rate-limit", () => ({
+  checkRateLimit: vi.fn(),
+  rateLimitHeaders: () => ({}),
+}));
+vi.mock("@/lib/idempotency", () => ({
+  withIdempotency:
+    <Args extends unknown[]>(fn: (...args: Args) => Promise<Response>) =>
+    (...args: Args) =>
+      fn(...args),
+}));
+vi.mock("@/lib/cache/invalidate", () => ({
+  invalidateUserMeasurements: vi.fn(),
+}));
+vi.mock("@/lib/insights/comprehensive-generate", () => ({
+  invalidateStatusInsightsForTypes: vi.fn().mockResolvedValue(undefined),
+}));
+vi.mock("@/lib/rollups/measurement-rollups", async () => {
+  const actual = await vi.importActual<
+    typeof import("@/lib/rollups/measurement-rollups")
+  >("@/lib/rollups/measurement-rollups");
+  return {
+    // keep the real collapse so the test exercises the actual fan-out logic
+    collapseToTypeDayKeys: actual.collapseToTypeDayKeys,
+    recomputeBucketsForMeasurement: vi.fn().mockResolvedValue(undefined),
+  };
+});
+vi.mock("@/lib/logging/transports", () => ({ emitIfSampled: vi.fn() }));
+vi.mock("@/lib/db-compat", () => ({
+  ensureDbCompatibility: vi.fn().mockResolvedValue(undefined),
+}));
+vi.mock("next/headers", () => ({
+  headers: vi.fn(async () => ({ get: () => null })),
+  cookies: vi.fn(async () => ({
+    get: () => undefined,
+    set: () => {},
+    delete: () => {},
+  })),
+}));
+
+import { POST } from "../route";
+import { prisma } from "@/lib/db";
+import { getSession } from "@/lib/auth/session";
+import { checkRateLimit } from "@/lib/rate-limit";
+import { invalidateUserMeasurements } from "@/lib/cache/invalidate";
+import { invalidateStatusInsightsForTypes } from "@/lib/insights/comprehensive-generate";
+import { recomputeBucketsForMeasurement } from "@/lib/rollups/measurement-rollups";
+
+const SESSION_OK = {
+  session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
+  user: { id: "user-1", username: "tester", role: "USER" as const },
+};
+
+function postReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/measurements/restore", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+beforeEach(() => {
+  vi.resetAllMocks();
+  vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+  vi.mocked(prisma.auditLog.create).mockResolvedValue({} as never);
+  vi.mocked(checkRateLimit).mockResolvedValue({ allowed: true } as never);
+  vi.mocked(recomputeBucketsForMeasurement).mockResolvedValue(undefined);
+  vi.mocked(invalidateStatusInsightsForTypes).mockResolvedValue(undefined);
+});
+
+describe("POST /api/measurements/restore", () => {
+  it("un-tombstones only owned, tombstoned rows and returns that count", async () => {
+    // Caller asked for 3 ids but only 2 are owned + tombstoned.
+    vi.mocked(prisma.measurement.findMany).mockResolvedValue([
+      { type: "WEIGHT", measuredAt: new Date("2026-01-01T08:00:00Z") },
+      { type: "WEIGHT", measuredAt: new Date("2026-01-01T20:00:00Z") },
+    ] as never);
+    vi.mocked(prisma.measurement.updateMany).mockResolvedValue({
+      count: 2,
+    } as never);
+
+    const res = await POST(postReq({ ids: ["m1", "m2", "foreign"] }));
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as { data: { restored: number } };
+    expect(body.data.restored).toBe(2);
+
+    // updateMany is ownership-scoped + only touches tombstones — a
+    // forged / live id never 404s, it's just excluded from the count.
+    const call = vi.mocked(prisma.measurement.updateMany).mock.calls[0][0];
+    expect(call.where).toMatchObject({
+      id: { in: ["m1", "m2", "foreign"] },
+      userId: "user-1",
+      deletedAt: { not: null },
+    });
+    expect(call.data).toMatchObject({
+      deletedAt: null,
+      syncVersion: { increment: 1 },
+    });
+
+    expect(invalidateUserMeasurements).toHaveBeenCalledWith("user-1");
+  });
+
+  it("collapses the rollup recompute to the unique (type, day) set, not per-row", async () => {
+    vi.mocked(prisma.measurement.findMany).mockResolvedValue([
+      { type: "WEIGHT", measuredAt: new Date("2026-01-01T08:00:00Z") },
+      { type: "WEIGHT", measuredAt: new Date("2026-01-01T20:00:00Z") },
+      { type: "WEIGHT", measuredAt: new Date("2026-01-02T09:00:00Z") },
+      { type: "PULSE", measuredAt: new Date("2026-01-01T10:00:00Z") },
+    ] as never);
+    vi.mocked(prisma.measurement.updateMany).mockResolvedValue({
+      count: 4,
+    } as never);
+
+    await POST(postReq({ ids: ["a", "b", "c", "d"] }));
+
+    // 4 rows in, 3 distinct (type, day) recomputes out.
+    expect(recomputeBucketsForMeasurement).toHaveBeenCalledTimes(3);
+  });
+
+  it("is a no-op (restored: 0) when no id is owned + tombstoned — no rollup, no invalidate", async () => {
+    vi.mocked(prisma.measurement.findMany).mockResolvedValue([] as never);
+    vi.mocked(prisma.measurement.updateMany).mockResolvedValue({
+      count: 0,
+    } as never);
+
+    const res = await POST(postReq({ ids: ["foreign-1", "live-1"] }));
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as { data: { restored: number } };
+    expect(body.data.restored).toBe(0);
+    expect(invalidateUserMeasurements).not.toHaveBeenCalled();
+    expect(recomputeBucketsForMeasurement).not.toHaveBeenCalled();
+  });
+
+  it("rejects a batch over the 200-id cap with 422", async () => {
+    const ids = Array.from({ length: 201 }, (_, i) => `m${i}`);
+    const res = await POST(postReq({ ids }));
+    expect(res.status).toBe(422);
+    expect(prisma.measurement.updateMany).not.toHaveBeenCalled();
+  });
+
+  it("rejects an empty id array with 422", async () => {
+    const res = await POST(postReq({ ids: [] }));
+    expect(res.status).toBe(422);
+  });
+
+  it("429s when the rate limit is exceeded", async () => {
+    vi.mocked(checkRateLimit).mockResolvedValue({ allowed: false } as never);
+    const res = await POST(postReq({ ids: ["m1"] }));
+    expect(res.status).toBe(429);
+    expect(prisma.measurement.updateMany).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/app/api/measurements/restore/route.ts b/src/app/api/measurements/restore/route.ts
new file mode 100644
index 000000000..178543fdb
--- /dev/null
+++ b/src/app/api/measurements/restore/route.ts
@@ -0,0 +1,144 @@
+/**
+ * `POST /api/measurements/restore` — un-tombstone for the management
+ * list's delete-Undo affordance (v1.16.4).
+ *
+ * Body:
+ *   { ids: string[] }   — 1..200 measurement ids, scoped to the caller.
+ *
+ * Clears `deletedAt` (+ bumps `syncVersion`) on every owned,
+ * currently-tombstoned row in one `updateMany`, so the row re-surfaces
+ * in normal reads and the `/api/sync/changes` delta feed carries it as
+ * an upsert to paired clients. A forged / foreign / not-deleted id is a
+ * silent no-op (never a 404 existence leak): the mutation `where` pins
+ * `userId` so it only ever touches the caller's rows.
+ *
+ * Response (200):
+ *   { restored: <number of rows un-tombstoned> }
+ */
+import { NextRequest } from "next/server";
+import { z } from "zod/v4";
+
+import { prisma } from "@/lib/db";
+import { apiHandler, requireAuth } from "@/lib/api-handler";
+import { annotate } from "@/lib/logging/context";
+import { auditLog } from "@/lib/auth/audit";
+import {
+  apiError,
+  apiSuccess,
+  getClientIp,
+  returnAllZodIssues,
+  safeJson,
+} from "@/lib/api-response";
+import { withIdempotency } from "@/lib/idempotency";
+import { checkRateLimit } from "@/lib/rate-limit";
+import { invalidateUserMeasurements } from "@/lib/cache/invalidate";
+import { invalidateStatusInsightsForTypes } from "@/lib/insights/comprehensive-generate";
+import {
+  recomputeBucketsForMeasurement,
+  collapseToTypeDayKeys,
+} from "@/lib/rollups/measurement-rollups";
+import type { MeasurementType } from "@/generated/prisma/client";
+
+const MAX_IDS_PER_BATCH = 200;
+const RATE_LIMIT_MAX = 60;
+const RATE_LIMIT_WINDOW_MS = 60 * 1000;
+
+const restoreSchema = z.object({
+  ids: z.array(z.string().min(1)).min(1).max(MAX_IDS_PER_BATCH),
+});
+
+export const POST = apiHandler(withIdempotency<[NextRequest]>(postRestore));
+
+async function postRestore(request: NextRequest): Promise<Response> {
+  const { user } = await requireAuth();
+
+  const rl = await checkRateLimit(
+    `measurements:restore:${user.id}`,
+    RATE_LIMIT_MAX,
+    RATE_LIMIT_WINDOW_MS,
+  );
+  if (!rl.allowed) {
+    return apiError("Too many restore requests, try again later", 429);
+  }
+
+  const { data: rawBody, error: jsonError } = await safeJson(request, {
+    maxBytes: 256 * 1024,
+  });
+  if (jsonError) return jsonError;
+
+  const parsed = restoreSchema.safeParse(rawBody);
+  if (!parsed.success) {
+    return returnAllZodIssues(parsed.error, 422, {
+      errorCode: "measurement.restore.invalid",
+    });
+  }
+
+  const { ids } = parsed.data;
+
+  // Read the soon-to-be-restored rows first so we know which
+  // `(type, day)` buckets need a rollup recompute and which types need
+  // a status-insight cache drop. Ownership-scoped + `deletedAt != null`
+  // so a forged / foreign / never-deleted id is excluded here exactly as
+  // it is from the mutation below — no existence leak.
+  const affected = await prisma.measurement.findMany({
+    where: { id: { in: ids }, userId: user.id, deletedAt: { not: null } },
+    select: { type: true, measuredAt: true },
+  });
+
+  // Un-tombstone in one statement. The `where` pins `userId` so a forged
+  // id for another user is silently a no-op; `deletedAt: { not: null }`
+  // keeps the count honest (a live row doesn't re-count).
+  const { count } = await prisma.measurement.updateMany({
+    where: { id: { in: ids }, userId: user.id, deletedAt: { not: null } },
+    data: { deletedAt: null, syncVersion: { increment: 1 } },
+  });
+
+  await auditLog("measurement.restore", {
+    userId: user.id,
+    ipAddress: getClientIp(request),
+    details: { count },
+  });
+
+  annotate({
+    action: { name: "measurement.restore" },
+    meta: { count },
+  });
+
+  if (count > 0) {
+    // Bust per-user analytics + achievements + workouts caches so
+    // subsequent reads reflect the restored rows.
+    invalidateUserMeasurements(user.id);
+
+    // Collapse the restored rows to the unique `(type, day)` set BEFORE
+    // recomputing — mirrors the bulk-delete path. Best-effort: a
+    // populator hiccup never fails the user's restore.
+    const keys = collapseToTypeDayKeys(
+      affected.map((row) => ({
+        type: row.type as MeasurementType,
+        measuredAt: row.measuredAt,
+      })),
+    );
+    try {
+      for (const k of keys) {
+        await recomputeBucketsForMeasurement(user.id, k.type, k.measuredAt);
+      }
+    } catch (err) {
+      console.warn("[measurements] restore rollup recompute failed", err);
+    }
+
+    // Drop the cached per-metric assessment rows the restore dirties so
+    // the next mount / nightly warm pass regenerates against the
+    // restored history. Fire-and-forget: never blocks the restore.
+    const affectedTypes = Array.from(new Set(keys.map((k) => k.type)));
+    if (affectedTypes.length > 0) {
+      invalidateStatusInsightsForTypes(user.id, affectedTypes).catch((err) => {
+        console.warn(
+          "[measurements] restore status-insight invalidate failed",
+          err,
+        );
+      });
+    }
+  }
+
+  return apiSuccess({ restored: count });
+}
diff --git a/src/app/api/measurements/route.ts b/src/app/api/measurements/route.ts
index 652da7bec..5ef8aedc5 100644
--- a/src/app/api/measurements/route.ts
+++ b/src/app/api/measurements/route.ts
@@ -319,7 +319,7 @@ export const GET = apiHandler(async (request: NextRequest) => {
   // `GET /api/measurements?type=…&aggregate=daily&limit=5000` requests
   // (BP_SYS / BP_DIA / WEIGHT). The legacy `date_trunc('day', …)`
   // path scanned the measurements table each time — a full year window
-  // on Marc's account hit 3 × ~3 s on the v1.4.35 HAR. Reading from
+  // on the maintainer's account hit 3 × ~3 s on the v1.4.35 HAR. Reading from
   // the persistent `measurement_rollups` DAY buckets drops each call
   // to a small indexed read against the ~5 k-row rollup table.
   //
@@ -398,7 +398,7 @@ export const GET = apiHandler(async (request: NextRequest) => {
     // window) and finishes well inside the request budget.
     //
     // The probe runs only on suspicious rollups so the covered-tenant
-    // happy path stays a single indexed read. Marc's tenant on a 30-day
+    // happy path stays a single indexed read. The maintainer's tenant on a 30-day
     // BP_SYS window pre-fix returned 2 rollup rows and hit `total: 2`
     // in the live trace; post-fix the probe finds ~30 distinct days in
     // `measurements`, folds them, and the chart paints all 30.
diff --git a/src/app/api/measurements/series/__tests__/route.test.ts b/src/app/api/measurements/series/__tests__/route.test.ts
index 8dc041f8a..1a8fd6a41 100644
--- a/src/app/api/measurements/series/__tests__/route.test.ts
+++ b/src/app/api/measurements/series/__tests__/route.test.ts
@@ -55,7 +55,7 @@ import { annotate } from "@/lib/logging/context";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(query: string): NextRequest {
diff --git a/src/app/api/medications/[id]/cadence/__tests__/route.test.ts b/src/app/api/medications/[id]/cadence/__tests__/route.test.ts
index 953273482..d734e5f30 100644
--- a/src/app/api/medications/[id]/cadence/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/cadence/__tests__/route.test.ts
@@ -39,7 +39,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/medications/[id]/compliance/__tests__/route.test.ts b/src/app/api/medications/[id]/compliance/__tests__/route.test.ts
index cea060613..7a644fb26 100644
--- a/src/app/api/medications/[id]/compliance/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/compliance/__tests__/route.test.ts
@@ -73,7 +73,7 @@ import { prisma } from "@/lib/db";
 import { getSession } from "@/lib/auth/session";
 import { cached } from "@/lib/cache/server-cache";
 import { checkRateLimit } from "@/lib/rate-limit";
-import { getUserTodayBounds } from "@/lib/timezone";
+import { getUserTodayBounds } from "@/lib/tz/local-day";
 import { userDayKey } from "@/lib/tz/format";
 
 // UTC keeps the half-open day slice (`[dayStart, dayEnd)`) and the
@@ -84,7 +84,7 @@ const TZ = "UTC";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const, timezone: TZ },
+  user: { id: "user-1", username: "testuser", role: "USER" as const, timezone: TZ },
 };
 
 const ROUTE_PARAMS = { params: Promise.resolve({ id: "med-1" }) };
diff --git a/src/app/api/medications/[id]/dose-history/__tests__/route.test.ts b/src/app/api/medications/[id]/dose-history/__tests__/route.test.ts
index 967a62714..c011c8f72 100644
--- a/src/app/api/medications/[id]/dose-history/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/dose-history/__tests__/route.test.ts
@@ -58,14 +58,14 @@ import { prisma } from "@/lib/db";
 import { getSession } from "@/lib/auth/session";
 import { assertMedicationOwnership } from "@/lib/medications/route-guards";
 import { checkRateLimit } from "@/lib/rate-limit";
-import { localHmAsUtc } from "@/lib/timezone";
+import { localHmAsUtc } from "@/lib/tz/local-day";
 
 const TZ = "Europe/Berlin";
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
   user: {
     id: "user-1",
-    username: "marc",
+    username: "testuser",
     role: "USER" as const,
     timezone: TZ,
   },
diff --git a/src/app/api/medications/[id]/glp1/__tests__/route.test.ts b/src/app/api/medications/[id]/glp1/__tests__/route.test.ts
index 93f8b6076..b9dfb690e 100644
--- a/src/app/api/medications/[id]/glp1/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/glp1/__tests__/route.test.ts
@@ -62,7 +62,7 @@ import { assertMedicationOwnership } from "@/lib/medications/route-guards";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 const MED_OK = { id: "med-1", userId: "user-1" };
diff --git a/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts b/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts
index 5a2e2751b..cc1223c6c 100644
--- a/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/intake/[eventId]/__tests__/route.test.ts
@@ -260,7 +260,7 @@ describe("PUT /api/medications/[id]/intake/[eventId] — one-shot reconcile on s
 // v1.15.18 — PUT re-runs window-band slot attribution on a takenAt change
 // ────────────────────────────────────────────────────────────────────
 
-import { localHmAsUtc } from "@/lib/timezone";
+import { localHmAsUtc } from "@/lib/tz/local-day";
 
 const TZ = "Europe/Berlin";
 const SESSION_TZ = {
diff --git a/src/app/api/medications/[id]/intake/__tests__/route.test.ts b/src/app/api/medications/[id]/intake/__tests__/route.test.ts
index 984f5fb73..a1ddc4662 100644
--- a/src/app/api/medications/[id]/intake/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/intake/__tests__/route.test.ts
@@ -98,7 +98,7 @@ const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
   user: {
     id: "user-1",
-    username: "marc",
+    username: "testuser",
     role: "USER" as const,
     // Pin the user timezone so slot-instant resolution is deterministic
     // regardless of the host TZ (CI runs in UTC, local in Europe/Berlin).
diff --git a/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts b/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts
index 1c3fef93e..f733a8821 100644
--- a/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/intake/bulk-delete/__tests__/route.test.ts
@@ -90,7 +90,7 @@ import {
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 const ROUTE_PARAMS = { params: Promise.resolve({ id: "med-1" }) };
diff --git a/src/app/api/medications/[id]/inventory/__tests__/route.test.ts b/src/app/api/medications/[id]/inventory/__tests__/route.test.ts
index 6ebf59818..4d23b8c1f 100644
--- a/src/app/api/medications/[id]/inventory/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/inventory/__tests__/route.test.ts
@@ -52,7 +52,7 @@ import { checkRateLimit } from "@/lib/rate-limit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 const MED_OK = { id: "med-1", userId: "user-1" };
diff --git a/src/app/api/medications/[id]/route.ts b/src/app/api/medications/[id]/route.ts
index 4cc161078..9b6517294 100644
--- a/src/app/api/medications/[id]/route.ts
+++ b/src/app/api/medications/[id]/route.ts
@@ -31,7 +31,7 @@ import {
   recomputeMedicationComplianceForDay,
 } from "@/lib/rollups/medication-compliance-rollups";
 import { assertMedicationOwnership } from "@/lib/medications/route-guards";
-import { getUserTodayBounds } from "@/lib/timezone";
+import { getUserTodayBounds } from "@/lib/tz/local-day";
 import { NextRequest } from "next/server";
 
 type RouteParams = { params: Promise<{ id: string }> };
diff --git a/src/app/api/medications/[id]/side-effects/[logId]/route.ts b/src/app/api/medications/[id]/side-effects/[logId]/route.ts
index e6fa10576..975e0797f 100644
--- a/src/app/api/medications/[id]/side-effects/[logId]/route.ts
+++ b/src/app/api/medications/[id]/side-effects/[logId]/route.ts
@@ -5,7 +5,7 @@
  *     - hard delete; the row is user-owned, non-clinical, and the
  *       audit log captures enough state to reconstruct it if needed.
  *
- * Marc-decision (from the W19d brief): allow delete at any time
+ * maintainer decision (from the W19d brief): allow delete at any time
  * rather than a 24-hour retraction window. Side-effect rows are not
  * a clinical record; the user owns them and a stale mis-entry should
  * never be undeletable. The audit trail preserves "what was deleted
diff --git a/src/app/api/medications/[id]/side-effects/__tests__/route.test.ts b/src/app/api/medications/[id]/side-effects/__tests__/route.test.ts
index d9b3594ef..015b19e08 100644
--- a/src/app/api/medications/[id]/side-effects/__tests__/route.test.ts
+++ b/src/app/api/medications/[id]/side-effects/__tests__/route.test.ts
@@ -60,7 +60,7 @@ import { checkRateLimit } from "@/lib/rate-limit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 const MED_OK = { id: "med-1", userId: "user-1" };
diff --git a/src/app/api/medications/__tests__/route.test.ts b/src/app/api/medications/__tests__/route.test.ts
index 50011d07d..cf47f9795 100644
--- a/src/app/api/medications/__tests__/route.test.ts
+++ b/src/app/api/medications/__tests__/route.test.ts
@@ -38,7 +38,7 @@ vi.mock("@/lib/medication-category", () => ({
   getMedicationCategories: vi.fn().mockResolvedValue({}),
   setMedicationCategory: vi.fn().mockResolvedValue(undefined),
 }));
-vi.mock("@/lib/timezone", () => ({
+vi.mock("@/lib/tz/local-day", () => ({
   getUserTodayBounds: vi
     .fn()
     .mockReturnValue({ start: new Date(), end: new Date() }),
diff --git a/src/app/api/medications/intake/__tests__/route.test.ts b/src/app/api/medications/intake/__tests__/route.test.ts
index 520646f98..d5f824d08 100644
--- a/src/app/api/medications/intake/__tests__/route.test.ts
+++ b/src/app/api/medications/intake/__tests__/route.test.ts
@@ -66,7 +66,7 @@ import { __resetAllCachesForTests } from "@/lib/cache/server-cache";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/medications/intake/route.ts b/src/app/api/medications/intake/route.ts
index ef19121db..e70c56ad3 100644
--- a/src/app/api/medications/intake/route.ts
+++ b/src/app/api/medications/intake/route.ts
@@ -34,7 +34,7 @@ import {
   expectedSlotCountForDay,
   lastNonSkippedTakenAt,
 } from "@/lib/analytics/compliance";
-import { getUserTodayBounds } from "@/lib/timezone";
+import { getUserTodayBounds } from "@/lib/tz/local-day";
 import { projectTodayIntakesAndRecompute } from "@/lib/medications/scheduling/project-today-intakes";
 import {
   applyCanonicalSlotWrite,
diff --git a/src/app/api/medications/route.ts b/src/app/api/medications/route.ts
index 1a784e619..2526095a9 100644
--- a/src/app/api/medications/route.ts
+++ b/src/app/api/medications/route.ts
@@ -19,7 +19,7 @@ import {
   computeDisplayDue,
   OVERDUE_LOOKBACK_MS,
 } from "@/lib/medications/scheduling/next-due";
-import { getUserTodayBounds } from "@/lib/timezone";
+import { getUserTodayBounds } from "@/lib/tz/local-day";
 import { invalidateUserMedications } from "@/lib/cache/invalidate";
 import { cached, caches, type ServerCache } from "@/lib/cache/server-cache";
 import { NextRequest } from "next/server";
diff --git a/src/app/api/mood-entries/restore/__tests__/route.test.ts b/src/app/api/mood-entries/restore/__tests__/route.test.ts
new file mode 100644
index 000000000..51772d529
--- /dev/null
+++ b/src/app/api/mood-entries/restore/__tests__/route.test.ts
@@ -0,0 +1,161 @@
+/**
+ * v1.16.4 — POST /api/mood-entries/restore.
+ *
+ * Asserts the ownership-scoped un-tombstone contract that backs the
+ * delete-Undo toast: only owned, currently-tombstoned rows are touched;
+ * a forged / foreign / never-deleted id is a silent no-op (no 404
+ * existence leak); the mood rollup recompute collapses to the unique
+ * day set; the >200-id cap returns 422.
+ */
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { NextRequest } from "next/server";
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    moodEntry: {
+      findMany: vi.fn(),
+      updateMany: vi.fn(),
+    },
+    auditLog: { create: vi.fn() },
+  },
+}));
+
+vi.mock("@/lib/auth/session", () => ({ getSession: vi.fn() }));
+vi.mock("@/lib/auth/audit", () => ({
+  auditLog: vi.fn().mockResolvedValue(undefined),
+}));
+vi.mock("@/lib/rate-limit", () => ({
+  checkRateLimit: vi.fn(),
+  rateLimitHeaders: () => ({}),
+}));
+vi.mock("@/lib/idempotency", () => ({
+  withIdempotency:
+    <Args extends unknown[]>(fn: (...args: Args) => Promise<Response>) =>
+    (...args: Args) =>
+      fn(...args),
+}));
+vi.mock("@/lib/cache/invalidate", () => ({
+  invalidateUserMood: vi.fn(),
+}));
+vi.mock("@/lib/rollups/mood-rollups", () => ({
+  recomputeMoodBucketsForEntry: vi.fn().mockResolvedValue(undefined),
+}));
+vi.mock("@/lib/logging/transports", () => ({ emitIfSampled: vi.fn() }));
+vi.mock("@/lib/db-compat", () => ({
+  ensureDbCompatibility: vi.fn().mockResolvedValue(undefined),
+}));
+vi.mock("next/headers", () => ({
+  headers: vi.fn(async () => ({ get: () => null })),
+  cookies: vi.fn(async () => ({
+    get: () => undefined,
+    set: () => {},
+    delete: () => {},
+  })),
+}));
+
+import { POST } from "../route";
+import { prisma } from "@/lib/db";
+import { getSession } from "@/lib/auth/session";
+import { checkRateLimit } from "@/lib/rate-limit";
+import { invalidateUserMood } from "@/lib/cache/invalidate";
+import { recomputeMoodBucketsForEntry } from "@/lib/rollups/mood-rollups";
+
+const SESSION_OK = {
+  session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
+  user: { id: "user-1", username: "tester", role: "USER" as const },
+};
+
+function postReq(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/mood-entries/restore", {
+    method: "POST",
+    headers: { "content-type": "application/json" },
+    body: JSON.stringify(body),
+  });
+}
+
+beforeEach(() => {
+  vi.resetAllMocks();
+  vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+  vi.mocked(prisma.auditLog.create).mockResolvedValue({} as never);
+  vi.mocked(checkRateLimit).mockResolvedValue({ allowed: true } as never);
+  vi.mocked(recomputeMoodBucketsForEntry).mockResolvedValue(undefined as never);
+});
+
+describe("POST /api/mood-entries/restore", () => {
+  it("un-tombstones only owned, tombstoned rows and returns that count", async () => {
+    vi.mocked(prisma.moodEntry.findMany).mockResolvedValue([
+      { moodLoggedAt: new Date("2026-01-01T08:00:00Z") },
+      { moodLoggedAt: new Date("2026-01-01T20:00:00Z") },
+    ] as never);
+    vi.mocked(prisma.moodEntry.updateMany).mockResolvedValue({
+      count: 2,
+    } as never);
+
+    const res = await POST(postReq({ ids: ["e1", "e2", "foreign"] }));
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as { data: { restored: number } };
+    expect(body.data.restored).toBe(2);
+
+    const call = vi.mocked(prisma.moodEntry.updateMany).mock.calls[0][0];
+    expect(call.where).toMatchObject({
+      id: { in: ["e1", "e2", "foreign"] },
+      userId: "user-1",
+      deletedAt: { not: null },
+    });
+    expect(call.data).toMatchObject({
+      deletedAt: null,
+      syncVersion: { increment: 1 },
+    });
+
+    expect(invalidateUserMood).toHaveBeenCalledWith("user-1");
+  });
+
+  it("collapses the mood rollup recompute to the unique day set, not per-row", async () => {
+    // 3 restored rows across 2 distinct UTC days → 2 recomputes.
+    vi.mocked(prisma.moodEntry.findMany).mockResolvedValue([
+      { moodLoggedAt: new Date("2026-01-01T08:00:00Z") },
+      { moodLoggedAt: new Date("2026-01-01T20:00:00Z") },
+      { moodLoggedAt: new Date("2026-01-02T09:00:00Z") },
+    ] as never);
+    vi.mocked(prisma.moodEntry.updateMany).mockResolvedValue({
+      count: 3,
+    } as never);
+
+    await POST(postReq({ ids: ["a", "b", "c"] }));
+
+    expect(recomputeMoodBucketsForEntry).toHaveBeenCalledTimes(2);
+  });
+
+  it("is a no-op (restored: 0) when no id is owned + tombstoned", async () => {
+    vi.mocked(prisma.moodEntry.findMany).mockResolvedValue([] as never);
+    vi.mocked(prisma.moodEntry.updateMany).mockResolvedValue({
+      count: 0,
+    } as never);
+
+    const res = await POST(postReq({ ids: ["foreign-1", "live-1"] }));
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as { data: { restored: number } };
+    expect(body.data.restored).toBe(0);
+    expect(invalidateUserMood).not.toHaveBeenCalled();
+    expect(recomputeMoodBucketsForEntry).not.toHaveBeenCalled();
+  });
+
+  it("rejects a batch over the 200-id cap with 422", async () => {
+    const ids = Array.from({ length: 201 }, (_, i) => `e${i}`);
+    const res = await POST(postReq({ ids }));
+    expect(res.status).toBe(422);
+    expect(prisma.moodEntry.updateMany).not.toHaveBeenCalled();
+  });
+
+  it("rejects an empty id array with 422", async () => {
+    const res = await POST(postReq({ ids: [] }));
+    expect(res.status).toBe(422);
+  });
+
+  it("429s when the rate limit is exceeded", async () => {
+    vi.mocked(checkRateLimit).mockResolvedValue({ allowed: false } as never);
+    const res = await POST(postReq({ ids: ["e1"] }));
+    expect(res.status).toBe(429);
+    expect(prisma.moodEntry.updateMany).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/app/api/mood-entries/restore/route.ts b/src/app/api/mood-entries/restore/route.ts
new file mode 100644
index 000000000..fd4ab345b
--- /dev/null
+++ b/src/app/api/mood-entries/restore/route.ts
@@ -0,0 +1,133 @@
+/**
+ * `POST /api/mood-entries/restore` — un-tombstone for the mood list's
+ * delete-Undo affordance (v1.16.4).
+ *
+ * Body:
+ *   { ids: string[] }   — 1..200 mood-entry ids, scoped to the caller.
+ *
+ * Clears `deletedAt` (+ bumps `syncVersion`) on every owned,
+ * currently-tombstoned row in one `updateMany`, so the row re-surfaces
+ * in normal reads and the `/api/sync/changes` delta feed carries it as
+ * an upsert to paired clients. A forged / foreign / not-deleted id is a
+ * silent no-op (never a 404 existence leak): the mutation `where` pins
+ * `userId` so it only ever touches the caller's rows.
+ *
+ * Response (200):
+ *   { restored: <number of rows un-tombstoned> }
+ */
+import { NextRequest } from "next/server";
+import { z } from "zod/v4";
+
+import { prisma } from "@/lib/db";
+import { apiHandler, requireAuth } from "@/lib/api-handler";
+import { annotate } from "@/lib/logging/context";
+import { auditLog } from "@/lib/auth/audit";
+import {
+  apiError,
+  apiSuccess,
+  getClientIp,
+  returnAllZodIssues,
+  safeJson,
+} from "@/lib/api-response";
+import { withIdempotency } from "@/lib/idempotency";
+import { checkRateLimit } from "@/lib/rate-limit";
+import { invalidateUserMood } from "@/lib/cache/invalidate";
+import { recomputeMoodBucketsForEntry } from "@/lib/rollups/mood-rollups";
+
+const MAX_IDS_PER_BATCH = 200;
+const RATE_LIMIT_MAX = 60;
+const RATE_LIMIT_WINDOW_MS = 60 * 1000;
+
+const restoreSchema = z.object({
+  ids: z.array(z.string().min(1)).min(1).max(MAX_IDS_PER_BATCH),
+});
+
+export const POST = apiHandler(withIdempotency<[NextRequest]>(postRestore));
+
+async function postRestore(request: NextRequest): Promise<Response> {
+  const { user } = await requireAuth();
+
+  const rl = await checkRateLimit(
+    `mood-entries:restore:${user.id}`,
+    RATE_LIMIT_MAX,
+    RATE_LIMIT_WINDOW_MS,
+  );
+  if (!rl.allowed) {
+    return apiError("Too many restore requests, try again later", 429);
+  }
+
+  const { data: rawBody, error: jsonError } = await safeJson(request, {
+    maxBytes: 256 * 1024,
+  });
+  if (jsonError) return jsonError;
+
+  const parsed = restoreSchema.safeParse(rawBody);
+  if (!parsed.success) {
+    return returnAllZodIssues(parsed.error, 422, {
+      errorCode: "mood.restore.invalid",
+    });
+  }
+
+  const { ids } = parsed.data;
+
+  // Read the soon-to-be-restored rows first so we know which days need
+  // a mood-rollup recompute. Ownership-scoped + `deletedAt != null` so a
+  // forged / foreign / never-deleted id is excluded here exactly as it
+  // is from the mutation below — no existence leak.
+  const affected = await prisma.moodEntry.findMany({
+    where: { id: { in: ids }, userId: user.id, deletedAt: { not: null } },
+    select: { moodLoggedAt: true },
+  });
+
+  // Un-tombstone in one statement. The `where` pins `userId` so a forged
+  // id for another user is silently a no-op; `deletedAt: { not: null }`
+  // keeps the count honest (a live row doesn't re-count).
+  const { count } = await prisma.moodEntry.updateMany({
+    where: { id: { in: ids }, userId: user.id, deletedAt: { not: null } },
+    data: { deletedAt: null, syncVersion: { increment: 1 } },
+  });
+
+  await auditLog("mood.restore", {
+    userId: user.id,
+    ipAddress: getClientIp(request),
+    details: { count },
+  });
+
+  annotate({
+    action: { name: "mood.restore" },
+    meta: { count },
+  });
+
+  if (count > 0) {
+    // Bust per-user mood + achievements + analytics caches.
+    invalidateUserMood(user.id);
+
+    // Collapse the restored rows to the unique `(user, dayStart)` set
+    // BEFORE recomputing — mirrors the bulk-delete path. Best-effort: a
+    // populator hiccup never fails the user's restore.
+    const touchedDayStarts = new Set<number>();
+    for (const row of affected) {
+      const d = row.moodLoggedAt;
+      touchedDayStarts.add(
+        Date.UTC(d.getUTCFullYear(), d.getUTCMonth(), d.getUTCDate()),
+      );
+    }
+    try {
+      await Promise.all(
+        Array.from(touchedDayStarts).map((t) =>
+          recomputeMoodBucketsForEntry(user.id, new Date(t)),
+        ),
+      );
+    } catch (rollupErr) {
+      annotate({
+        meta: {
+          mood_rollup_write_failed: true,
+          mood_rollup_write_error:
+            rollupErr instanceof Error ? rollupErr.message : String(rollupErr),
+        },
+      });
+    }
+  }
+
+  return apiSuccess({ restored: count });
+}
diff --git a/src/app/api/mood/analytics/__tests__/route.test.ts b/src/app/api/mood/analytics/__tests__/route.test.ts
index 8db206d4e..3884ddcdd 100644
--- a/src/app/api/mood/analytics/__tests__/route.test.ts
+++ b/src/app/api/mood/analytics/__tests__/route.test.ts
@@ -70,7 +70,7 @@ import { __resetAllCachesForTests } from "@/lib/cache/server-cache";
 
 const SESSION_USER = {
   id: "user-mood-1",
-  username: "marc",
+  username: "testuser",
   role: "USER" as const,
   timezone: "Europe/Berlin",
   heightCm: 180,
diff --git a/src/app/api/notifications/status/__tests__/route.test.ts b/src/app/api/notifications/status/__tests__/route.test.ts
index 5bc64b78f..dac4be431 100644
--- a/src/app/api/notifications/status/__tests__/route.test.ts
+++ b/src/app/api/notifications/status/__tests__/route.test.ts
@@ -58,7 +58,7 @@ import { EVENT_TYPES } from "@/lib/notifications/types";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
diff --git a/src/app/api/onboarding/__tests__/step.test.ts b/src/app/api/onboarding/__tests__/step.test.ts
index 98a728d09..0f8f3b06c 100644
--- a/src/app/api/onboarding/__tests__/step.test.ts
+++ b/src/app/api/onboarding/__tests__/step.test.ts
@@ -63,7 +63,7 @@ import { checkRateLimit } from "@/lib/rate-limit";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(body: unknown): NextRequest {
diff --git a/src/app/api/personal-records/__tests__/route.test.ts b/src/app/api/personal-records/__tests__/route.test.ts
index e5a2ccff4..2fb56b4f3 100644
--- a/src/app/api/personal-records/__tests__/route.test.ts
+++ b/src/app/api/personal-records/__tests__/route.test.ts
@@ -36,7 +36,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(url: string): NextRequest {
diff --git a/src/app/api/sleep/night/__tests__/route.test.ts b/src/app/api/sleep/night/__tests__/route.test.ts
index a4ee765d4..509e7854a 100644
--- a/src/app/api/sleep/night/__tests__/route.test.ts
+++ b/src/app/api/sleep/night/__tests__/route.test.ts
@@ -46,7 +46,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function req(query: string): NextRequest {
diff --git a/src/app/api/user/profile/__tests__/route.test.ts b/src/app/api/user/profile/__tests__/route.test.ts
index e57697711..67b6568f7 100644
--- a/src/app/api/user/profile/__tests__/route.test.ts
+++ b/src/app/api/user/profile/__tests__/route.test.ts
@@ -34,7 +34,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 beforeEach(() => {
@@ -56,9 +56,9 @@ describe("GET /api/user/profile", () => {
   it("returns flattened iOS-style fields", async () => {
     vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
     vi.mocked(prisma.user.findUnique).mockResolvedValue({
-      username: "marc",
+      username: "testuser",
       displayName: "Alex T.",
-      email: "marc@example.com",
+      email: "user@example.com",
       dateOfBirth: new Date("1985-03-12T00:00:00.000Z"),
       gender: "MALE",
       heightCm: 180,
@@ -76,7 +76,7 @@ describe("GET /api/user/profile", () => {
         locale: string | null;
       };
     };
-    expect(body.data.username).toBe("marc");
+    expect(body.data.username).toBe("testuser");
     expect(body.data.displayName).toBe("Alex T.");
     expect(body.data.heightCm).toBe(180);
     expect(body.data.locale).toBe("de");
@@ -85,7 +85,7 @@ describe("GET /api/user/profile", () => {
   it("echoes the insurer IK number on GET", async () => {
     vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
     vi.mocked(prisma.user.findUnique).mockResolvedValue({
-      username: "marc",
+      username: "testuser",
       displayName: null,
       email: null,
       dateOfBirth: null,
@@ -136,7 +136,7 @@ describe("PATCH /api/user/profile", () => {
     vi.mocked(prisma.user.findUnique).mockResolvedValue(null);
     vi.mocked(prisma.user.update).mockResolvedValue({
       id: "user-1",
-      username: "marc",
+      username: "testuser",
       displayName: "Alex T.",
       email: null,
       role: "USER",
@@ -165,7 +165,7 @@ describe("PATCH /api/user/profile", () => {
     vi.mocked(prisma.user.findUnique).mockResolvedValue(null);
     vi.mocked(prisma.user.update).mockResolvedValue({
       id: "user-1",
-      username: "marc",
+      username: "testuser",
       displayName: null,
       email: null,
       role: "USER",
@@ -209,7 +209,7 @@ describe("PATCH /api/user/profile", () => {
     vi.mocked(prisma.user.findUnique).mockResolvedValue(null);
     vi.mocked(prisma.user.update).mockResolvedValue({
       id: "user-1",
-      username: "marc",
+      username: "testuser",
       displayName: null,
       email: null,
       role: "USER",
diff --git a/src/app/api/workouts/__tests__/batch-create.test.ts b/src/app/api/workouts/__tests__/batch-create.test.ts
index e834f4abb..084b95cfe 100644
--- a/src/app/api/workouts/__tests__/batch-create.test.ts
+++ b/src/app/api/workouts/__tests__/batch-create.test.ts
@@ -76,7 +76,7 @@ import { enqueuePrDetection } from "@/lib/jobs/pr-detection";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function makeRequest(
diff --git a/src/app/api/workouts/__tests__/canonical-dedup.test.ts b/src/app/api/workouts/__tests__/canonical-dedup.test.ts
index c24ad2064..de21ca911 100644
--- a/src/app/api/workouts/__tests__/canonical-dedup.test.ts
+++ b/src/app/api/workouts/__tests__/canonical-dedup.test.ts
@@ -52,7 +52,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function makeRequest(query = ""): NextRequest {
diff --git a/src/app/api/workouts/__tests__/detail.test.ts b/src/app/api/workouts/__tests__/detail.test.ts
index 57c2b1055..683a53c5d 100644
--- a/src/app/api/workouts/__tests__/detail.test.ts
+++ b/src/app/api/workouts/__tests__/detail.test.ts
@@ -50,7 +50,7 @@ import { getSession } from "@/lib/auth/session";
 
 const SESSION_OK = {
   session: { id: "sess-1", expiresAt: new Date(Date.now() + 3_600_000) },
-  user: { id: "user-1", username: "marc", role: "USER" as const },
+  user: { id: "user-1", username: "testuser", role: "USER" as const },
 };
 
 function makeRequest(): NextRequest {
diff --git a/src/app/auth/login/page.tsx b/src/app/auth/login/page.tsx
index 99bf541ed..25b3f7998 100644
--- a/src/app/auth/login/page.tsx
+++ b/src/app/auth/login/page.tsx
@@ -13,6 +13,7 @@ import { Separator } from "@/components/ui/separator";
 import { describePasskeyError } from "@/lib/passkey-errors";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { ApiError, apiGet, apiPost } from "@/lib/api/api-fetch";
 
 export default function LoginPage() {
   const router = useRouter();
@@ -33,12 +34,16 @@ export default function LoginPage() {
   const { data: registrationEnabled } = useQuery({
     queryKey: queryKeys.authRegistrationStatus(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/registration-status", {
-        cache: "no-store",
-      });
-      if (!res.ok) return true;
-      const json = await res.json();
-      return Boolean(json.data?.registrationEnabled ?? true);
+      try {
+        const data = await apiGet<{ registrationEnabled?: boolean }>(
+          "/api/auth/registration-status",
+          { cache: "no-store" },
+        );
+        return Boolean(data?.registrationEnabled ?? true);
+      } catch {
+        // Fail open, exactly as the raw `if (!res.ok) return true` did.
+        return true;
+      }
     },
     staleTime: 60 * 1000,
   });
@@ -58,38 +63,30 @@ export default function LoginPage() {
     setLoading(true);
 
     try {
-      const optRes = await fetch("/api/auth/passkey/login-options", {
-        method: "POST",
-      });
-      const optJson = await optRes.json();
-      if (!optRes.ok) {
-        setError(optJson.error);
-        setLoading(false);
-        return;
-      }
-
-      const { options, challengeId } = optJson.data;
       const { startAuthentication } = await import("@simplewebauthn/browser");
+      const { options, challengeId } = await apiPost<{
+        options: Parameters<typeof startAuthentication>[0]["optionsJSON"];
+        challengeId: string;
+      }>("/api/auth/passkey/login-options");
+
       const credential = await startAuthentication({ optionsJSON: options });
 
-      const verifyRes = await fetch("/api/auth/passkey/login-verify", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ challengeId, credential }),
+      await apiPost("/api/auth/passkey/login-verify", {
+        challengeId,
+        credential,
       });
 
-      const verifyJson = await verifyRes.json();
-      if (!verifyRes.ok) {
-        setError(verifyJson.error || t("auth.loginFailed"));
-        setLoading(false);
-        return;
-      }
-
       await queryClient.invalidateQueries({ queryKey: queryKeys.auth() });
       router.push(getRedirectTarget());
     } catch (err) {
-      const { key, params } = describePasskeyError(err);
-      setError(t(key, params));
+      // Route rejections carry the envelope error verbatim; everything
+      // else (WebAuthn ceremony failures) keeps the descriptive mapping.
+      if (err instanceof ApiError) {
+        setError(err.message || t("auth.loginFailed"));
+      } else {
+        const { key, params } = describePasskeyError(err);
+        setError(t(key, params));
+      }
     } finally {
       setLoading(false);
     }
@@ -101,23 +98,16 @@ export default function LoginPage() {
     setLoading(true);
 
     try {
-      const res = await fetch("/api/auth/login", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ email, password }),
-      });
-
-      const json = await res.json();
-      if (!res.ok) {
-        setError(json.error);
-        setLoading(false);
-        return;
-      }
+      await apiPost("/api/auth/login", { email, password });
 
       await queryClient.invalidateQueries({ queryKey: queryKeys.auth() });
       router.push(getRedirectTarget());
-    } catch {
-      setError(t("auth.loginFailed"));
+    } catch (err) {
+      setError(
+        err instanceof ApiError && err.message
+          ? err.message
+          : t("auth.loginFailed"),
+      );
     } finally {
       setLoading(false);
     }
diff --git a/src/app/auth/register/page.tsx b/src/app/auth/register/page.tsx
index 417d5f5d3..4c6173af1 100644
--- a/src/app/auth/register/page.tsx
+++ b/src/app/auth/register/page.tsx
@@ -13,6 +13,7 @@ import { PasswordStrength } from "@/components/ui/password-strength";
 import { useTranslations } from "@/lib/i18n/context";
 import { detectBrowserTimezone } from "@/lib/tz/format";
 import { queryKeys } from "@/lib/query-keys";
+import { ApiError, apiPost } from "@/lib/api/api-fetch";
 
 export default function RegisterPage() {
   const router = useRouter();
@@ -47,29 +48,22 @@ export default function RegisterPage() {
       // bogus, so a tampered or proxied request can never poison
       // the user's stored zone.
       const timezone = detectBrowserTimezone();
-      const res = await fetch("/api/auth/register", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          email,
-          username,
-          password,
-          timezone,
-          ...(inviteToken ? { inviteToken } : {}),
-        }),
+      await apiPost("/api/auth/register", {
+        email,
+        username,
+        password,
+        timezone,
+        ...(inviteToken ? { inviteToken } : {}),
       });
 
-      const json = await res.json();
-      if (!res.ok) {
-        setError(json.error);
-        setLoading(false);
-        return;
-      }
-
       await queryClient.invalidateQueries({ queryKey: queryKeys.auth() });
       router.push("/");
-    } catch {
-      setError(t("auth.registerFailed"));
+    } catch (err) {
+      setError(
+        err instanceof ApiError && err.message
+          ? err.message
+          : t("auth.registerFailed"),
+      );
     } finally {
       setLoading(false);
     }
diff --git a/src/app/bugreport/page.tsx b/src/app/bugreport/page.tsx
index 0273dea5f..ff1898f4a 100644
--- a/src/app/bugreport/page.tsx
+++ b/src/app/bugreport/page.tsx
@@ -17,6 +17,7 @@ import {
 import { Loader2, CheckCircle2, Bug, GitPullRequest, Info } from "lucide-react";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { ApiError, apiGet, apiPost } from "@/lib/api/api-fetch";
 
 interface BugReportStatus {
   configured: boolean;
@@ -49,10 +50,7 @@ export default function BugReportPage() {
   const { data: status } = useQuery({
     queryKey: queryKeys.bugreportStatus(),
     queryFn: async () => {
-      const res = await fetch("/api/bugreport/status");
-      if (!res.ok) throw new Error("Failed to load status");
-      const json = await res.json();
-      return json.data as BugReportStatus;
+      return apiGet<BugReportStatus>("/api/bugreport/status");
     },
     enabled: isAuthenticated,
   });
@@ -63,36 +61,28 @@ export default function BugReportPage() {
     setLoading(true);
 
     try {
-      const res = await fetch("/api/feedback", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          category,
-          subject: subject || description.slice(0, 60),
-          description,
-          metadata: {
-            locale,
-            userAgent:
-              typeof navigator !== "undefined" ? navigator.userAgent : null,
-            url:
-              typeof window !== "undefined" ? window.location.pathname : null,
-          },
-        }),
+      await apiPost("/api/feedback", {
+        category,
+        subject: subject || description.slice(0, 60),
+        description,
+        metadata: {
+          locale,
+          userAgent:
+            typeof navigator !== "undefined" ? navigator.userAgent : null,
+          url: typeof window !== "undefined" ? window.location.pathname : null,
+        },
+      });
+      setResult({ type: "success", message: t("bugreport.success") });
+      setSubject("");
+      setDescription("");
+    } catch (err) {
+      setResult({
+        type: "error",
+        message:
+          err instanceof ApiError
+            ? err.message || t("bugreport.errorCreating")
+            : t("common.networkError"),
       });
-
-      const json = await res.json();
-      if (res.ok) {
-        setResult({ type: "success", message: t("bugreport.success") });
-        setSubject("");
-        setDescription("");
-      } else {
-        setResult({
-          type: "error",
-          message: json.error || t("bugreport.errorCreating"),
-        });
-      }
-    } catch {
-      setResult({ type: "error", message: t("common.networkError") });
     } finally {
       setLoading(false);
     }
diff --git a/src/app/insights/medications/page.tsx b/src/app/insights/medications/page.tsx
index fd74c703b..de9400130 100644
--- a/src/app/insights/medications/page.tsx
+++ b/src/app/insights/medications/page.tsx
@@ -19,6 +19,7 @@ import { InsightStatusCard } from "@/components/insights/insight-status-card";
 import { MetricTargetSummary } from "@/components/insights/metric-target-summary";
 import { SubPageShell } from "@/components/insights/sub-page-shell";
 import { TileHeader } from "@/components/insights/tile-header";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W4 — `/insights/medications`.
@@ -93,10 +94,7 @@ export default function InsightsMedikamentePage() {
   const { data: comprehensive, isLoading: isComprehensiveLoading } = useQuery({
     queryKey: queryKeys.insightsComprehensive(),
     queryFn: async () => {
-      const res = await fetch("/api/insights/comprehensive");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as ComprehensiveMedicationData;
+      return apiGet<ComprehensiveMedicationData>("/api/insights/comprehensive");
     },
     enabled: isAuthenticated,
   });
@@ -110,13 +108,7 @@ export default function InsightsMedikamentePage() {
         MED_STATUS_TIMEOUT_MS,
       );
       try {
-        const res = await fetch(
-          `/api/insights/medication-compliance-status?locale=${locale}`,
-          { signal: controller.signal },
-        );
-        if (!res.ok) throw new Error("Failed");
-        const json = await res.json();
-        return json.data as MedicationComplianceStatusData;
+        return apiGet<MedicationComplianceStatusData>(`/api/insights/medication-compliance-status?locale=${locale}`, { signal: controller.signal });
       } finally {
         clearTimeout(timeoutHandle);
       }
@@ -313,10 +305,15 @@ function MedicationComplianceCalendar({
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.medicationComplianceChart(medicationId),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medicationId}/compliance`);
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as MedicationComplianceDailyResponse;
+      try {
+        return await apiGet<MedicationComplianceDailyResponse>(
+          `/api/medications/${medicationId}/compliance`,
+        );
+      } catch {
+        // The calendar simply doesn't render — same as the raw
+        // `if (!res.ok) return null` did.
+        return null;
+      }
     },
     enabled: !!medicationId,
     staleTime: 60 * 1000,
diff --git a/src/app/insights/mood/page.tsx b/src/app/insights/mood/page.tsx
index 442bfb78f..9f0324a08 100644
--- a/src/app/insights/mood/page.tsx
+++ b/src/app/insights/mood/page.tsx
@@ -16,6 +16,7 @@ import { MetricTargetSummary } from "@/components/insights/metric-target-summary
 import { MoodInsightsSections } from "@/components/insights/mood/mood-insights-sections";
 import { SlugInsightStatusCard } from "@/components/insights/slug-insight-status-card";
 import { SubPageShell } from "@/components/insights/sub-page-shell";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W4 — `/insights/mood`.
@@ -49,10 +50,7 @@ export default function InsightsStimmungPage() {
   const { data: comprehensive } = useQuery({
     queryKey: queryKeys.insightsComprehensive(),
     queryFn: async () => {
-      const res = await fetch("/api/insights/comprehensive");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as ComprehensiveMoodData;
+      return apiGet<ComprehensiveMoodData>("/api/insights/comprehensive");
     },
     enabled: isAuthenticated,
   });
diff --git a/src/app/insights/page.tsx b/src/app/insights/page.tsx
index 2a70b643e..a186d4541 100644
--- a/src/app/insights/page.tsx
+++ b/src/app/insights/page.tsx
@@ -8,6 +8,7 @@ import { RefreshCw, SlidersHorizontal, TrendingUp } from "lucide-react";
 
 import { useAuth } from "@/hooks/use-auth";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { useFeatureFlags } from "@/hooks/use-feature-flags";
 import { useInsightsLayoutQuery } from "@/hooks/use-insights-layout";
 import {
@@ -202,7 +203,7 @@ const CycleRingTile = dynamic(
  *     cards moved onto the metric pages they belong to (Weight owns
  *     weight × weekday, Pulse owns mood × pulse, …), so the overview
  *     no longer renders a duplicate correlation row.
- *   - The CoachDrawer is mounted in the mother-page body only (Marc
+ *   - The CoachDrawer is mounted in the mother-page body only (the maintainer
  *     directive). Navigating to a sub-page unmounts the drawer.
  *
  * The per-section status cards (BP/Weight/Pulse/etc.) and their
@@ -250,10 +251,11 @@ export default function InsightsPage() {
   const { data, isLoading, isFetched, isError, refetch } = useQuery({
     queryKey: queryKeys.insightsComprehensive(),
     queryFn: async () => {
-      const res = await fetch("/api/insights/comprehensive");
-      if (!res.ok) throw new Error(t("insights.loadError"));
-      const json = await res.json();
-      return json.data as ComprehensiveData;
+      try {
+        return await apiGet<ComprehensiveData>("/api/insights/comprehensive");
+      } catch {
+        throw new Error(t("insights.loadError"));
+      }
     },
     enabled: isAuthenticated,
   });
diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index caae60d0c..fd621644e 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -8,6 +8,7 @@ import { MonitoringBootstrap } from "@/components/monitoring/bootstrap";
 import { WebVitalsReporter } from "@/components/monitoring/web-vitals-reporter";
 import { parseLocaleFromAcceptLanguage } from "@/lib/format-locale";
 import { locales, type Locale } from "@/lib/i18n/config";
+import { allMessages } from "@/lib/i18n/shared-resolve";
 
 async function resolveInitialLocale(): Promise<Locale> {
   // Both cookies() and headers() can throw (DynamicServerError, etc.) —
@@ -106,6 +107,13 @@ export default async function RootLayout({
       : undefined;
 
   const initialLocale = await resolveInitialLocale();
+  // RSC handoff for the i18n bundle split: only EN ships statically in
+  // the client chunk, so a non-EN first paint needs its bundle inlined
+  // into the payload here — that is what keeps the split free of the
+  // EN→DE hydration flash. EN passes nothing (the client already holds
+  // the static fallback floor).
+  const initialMessages =
+    initialLocale === "en" ? undefined : allMessages[initialLocale];
 
   return (
     <html lang={initialLocale} suppressHydrationWarning>
@@ -117,7 +125,7 @@ export default async function RootLayout({
         />
       </head>
       <body className={`${inter.variable} font-sans antialiased`}>
-        <Providers initialLocale={initialLocale}>
+        <Providers initialLocale={initialLocale} initialMessages={initialMessages}>
           <MonitoringBootstrap />
           <WebVitalsReporter />
           {/* `DEMO_MODE` is a server-only env var; the proxy uses it to
diff --git a/src/app/medications/[id]/page.tsx b/src/app/medications/[id]/page.tsx
index 9a90a1d8a..b8f898195 100644
--- a/src/app/medications/[id]/page.tsx
+++ b/src/app/medications/[id]/page.tsx
@@ -28,6 +28,7 @@ import {
   MedicationDetailTabs,
   type MedicationDetailSnapshot,
 } from "@/components/medications/detail/MedicationDetailTabs";
+import { apiGet } from "@/lib/api/api-fetch";
 
 export default function MedicationDetailPage({
   params,
@@ -52,9 +53,7 @@ export default function MedicationDetailPage({
   } = useQuery<MedicationDetailSnapshot>({
     queryKey: queryKeys.medicationDetail(id),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${id}`);
-      if (!res.ok) throw new Error("medication_detail_failed");
-      return (await res.json()).data as MedicationDetailSnapshot;
+      return apiGet<MedicationDetailSnapshot>(`/api/medications/${id}`);
     },
     // v1.15.20 — deliberately NOT gated on `isAuthenticated`: the session
     // cookie rides the fetch either way, so waiting for `/api/auth/me`
diff --git a/src/app/medications/page.tsx b/src/app/medications/page.tsx
index 1d19ad058..f061a6599 100644
--- a/src/app/medications/page.tsx
+++ b/src/app/medications/page.tsx
@@ -21,6 +21,7 @@ import {
 import { EmptyState } from "@/components/ui/empty-state";
 import { Skeleton } from "@/components/ui/skeleton";
 import { CheckCircle2, Loader2, Pill, Plus } from "lucide-react";
+import { apiGet } from "@/lib/api/api-fetch";
 
 interface Schedule {
   id: string;
@@ -149,10 +150,7 @@ export default function MedicationsPage() {
   } = useQuery({
     queryKey: queryKeys.medications(),
     queryFn: async () => {
-      const res = await fetch("/api/medications");
-      if (!res.ok) throw new Error("Failed to fetch");
-      const json = await res.json();
-      return json.data as Medication[];
+      return apiGet<Medication[]>("/api/medications");
     },
     enabled: isAuthenticated,
   });
diff --git a/src/app/notifications/page.tsx b/src/app/notifications/page.tsx
index 8262fae20..e6b01e62a 100644
--- a/src/app/notifications/page.tsx
+++ b/src/app/notifications/page.tsx
@@ -19,6 +19,7 @@ import {
   type EventType,
 } from "@/lib/notifications/types";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet, apiPut } from "@/lib/api/api-fetch";
 
 interface ChannelInfo {
   id: string;
@@ -91,10 +92,7 @@ export default function NotificationsPage() {
   const { data, isLoading, isError } = useQuery({
     queryKey: queryKeys.notificationsPreferences(),
     queryFn: async () => {
-      const res = await fetch("/api/notifications/preferences");
-      if (!res.ok) throw new Error("Failed to load preferences");
-      const json = await res.json();
-      return json.data as PreferencesData;
+      return apiGet<PreferencesData>("/api/notifications/preferences");
     },
     enabled: isAuthenticated,
   });
@@ -105,13 +103,7 @@ export default function NotificationsPage() {
       eventType: string;
       enabled: boolean;
     }) => {
-      const res = await fetch("/api/notifications/preferences", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(params),
-      });
-      if (!res.ok) throw new Error("Failed to update preference");
-      return res.json();
+      return apiPut("/api/notifications/preferences", params);
     },
     onMutate: async ({ channelId, eventType, enabled }) => {
       await queryClient.cancelQueries({
diff --git a/src/app/onboarding/[step]/page.tsx b/src/app/onboarding/[step]/page.tsx
index cdf330960..ea9c4d44e 100644
--- a/src/app/onboarding/[step]/page.tsx
+++ b/src/app/onboarding/[step]/page.tsx
@@ -89,7 +89,7 @@ export default async function OnboardingStepPage({ params }: PageProps) {
   // Welcome (step 0)
   //   * Fresh user → value-prop carousel.
   //   * Returning user (onboarding already completed) → welcome-back
-  //     banner with "Open dashboard" CTA. Marc note 2026-05-14: the
+  //     banner with "Open dashboard" CTA. The maintainer note 2026-05-14: the
   //     "restart onboarding" affordance lives in Settings → Account in
   //     v1.4.26; for now the banner is informational only.
   if (requested === 0) {
diff --git a/src/app/page.tsx b/src/app/page.tsx
index 670620e50..e2aba1d5f 100644
--- a/src/app/page.tsx
+++ b/src/app/page.tsx
@@ -96,6 +96,7 @@ import {
   getAgeFromDateOfBirth,
   getPersonalizedPulseTarget,
 } from "@/lib/analytics/pulse-targets";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.7.0 — first-paint gate for the dashboard tile strip.
@@ -148,7 +149,7 @@ export default function DashboardPage() {
   // (thick slice) blocked every per-type tile until the heavy fan-out
   // resolved. Mood and medication tiles paint from their own dedicated
   // endpoints and arrived first; the per-type measurement tiles then
-  // arrived as one burst once the full slice landed — Marc reported
+  // arrived as one burst once the full slice landed — the maintainer reported
   // this "blocked-then-burst" pattern as "etwas nervig".
   //
   // Post-fix: two parallel queries. The slim slice (`?slice=summaries`)
@@ -205,7 +206,7 @@ export default function DashboardPage() {
     // coverage. Pre-fix the inline `slim?.summaries ?? thick?.summaries`
     // short-circuited on a truthy-but-empty `{}` from the slim slice
     // and blanked the tile strip even when thick carried the full
-    // payload — the regression Marc's v1.4.39.3 e2e CI flagged across
+    // payload — the regression the maintainer's v1.4.39.3 e2e CI flagged across
     // eight dashboard / chart specs. The helper falls back to thick
     // when slim resolves with no content and otherwise keeps the
     // v1.4.39.2 slim-wins-first progressive-paint contract.
@@ -237,10 +238,7 @@ export default function DashboardPage() {
   const { data: layoutDataLegacy } = useQuery({
     queryKey: queryKeys.dashboardWidgets(),
     queryFn: async () => {
-      const res = await fetch("/api/dashboard/widgets");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as DashboardLayout;
+      return apiGet<DashboardLayout>("/api/dashboard/widgets");
     },
     enabled: !snapshotEnabled && isAuthenticated,
     ...DASHBOARD_QUERY_OPTS,
@@ -252,13 +250,10 @@ export default function DashboardPage() {
   const { data: moodDataLegacy } = useQuery({
     queryKey: queryKeys.moodAnalytics(),
     queryFn: async () => {
-      const res = await fetch("/api/mood/analytics");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as {
+      return apiGet<{
         entries: Array<{ date: string; score: number; samples: number }>;
         summary: DataSummary;
-      };
+      }>("/api/mood/analytics");
     },
     enabled: !snapshotEnabled && isAuthenticated,
     ...DASHBOARD_QUERY_OPTS,
@@ -1362,7 +1357,7 @@ export default function DashboardPage() {
         return (
           <>
             {/* v1.4: dashboard tiles are *always* a single row.
-             * maintainer-explicit (per feedback_dashboard_one_row.md): a 2-row
+             * Maintainer-explicit (per feedback_dashboard_one_row.md): a 2-row
              * tile strip breaks the visual hierarchy and reads like an
              * Excel grid. Total width caps at the parent container —
              * exactly the chart-width below. When the active tile count
diff --git a/src/app/privacy/__tests__/page.test.tsx b/src/app/privacy/__tests__/page.test.tsx
index 378bd4242..982688f16 100644
--- a/src/app/privacy/__tests__/page.test.tsx
+++ b/src/app/privacy/__tests__/page.test.tsx
@@ -245,10 +245,11 @@ describe("<PrivacyPage>", () => {
     // email address attaches the actual contact.
     expect(html).toContain("mailto:mbombeck@gmail.com");
     expect(html).toContain("github.com/MBombeck/HealthLog/issues");
-    // Marc-Voice rule: no personal name in user-facing artefacts. The
-    // policy speaks in terms of "the operator" / "the controller"
-    // not Marc's full name. Only the bare email address attaches the
-    // contact route.
+    // Project-voice rule: no personal name in user-facing artefacts.
+    // The policy speaks in terms of "the operator" / "the controller",
+    // never a person's full name. Only the bare email address attaches
+    // the contact route. The regexes pin the operator's given-name /
+    // surname fragments so a regression cannot reintroduce them.
     expect(html).not.toMatch(/Marc[- ]?Andr/i);
     expect(html).not.toMatch(/\bBombeck\s+[A-Z]/);
   });
diff --git a/src/components/admin/__tests__/ai-quality-section.test.tsx b/src/components/admin/__tests__/ai-quality-section.test.tsx
index 84f1767e3..e8ce2fea5 100644
--- a/src/components/admin/__tests__/ai-quality-section.test.tsx
+++ b/src/components/admin/__tests__/ai-quality-section.test.tsx
@@ -58,7 +58,7 @@ describe("<AiQualitySection>", () => {
     mockQueryState.isError = false;
     const html = render(<AiQualitySection />);
     // v1.4.33 IW7 — admin section renamed from "AI Quality" to
-    // "Insights Quality" per the Marc-Voice rule.
+    // "Insights Quality" per the project-voice rule.
     expect(html).toContain("Insights Quality");
     expect(html).toContain("No feedback yet");
   });
diff --git a/src/components/admin/__tests__/api-token-no-collapse.test.tsx b/src/components/admin/__tests__/api-token-no-collapse.test.tsx
index f0925514d..1b262e136 100644
--- a/src/components/admin/__tests__/api-token-no-collapse.test.tsx
+++ b/src/components/admin/__tests__/api-token-no-collapse.test.tsx
@@ -35,8 +35,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
diff --git a/src/components/admin/__tests__/api-token-overview-responsive.test.tsx b/src/components/admin/__tests__/api-token-overview-responsive.test.tsx
index 69aa06562..4ab40afa5 100644
--- a/src/components/admin/__tests__/api-token-overview-responsive.test.tsx
+++ b/src/components/admin/__tests__/api-token-overview-responsive.test.tsx
@@ -30,7 +30,7 @@ const sampleTokens = [
     expiresAt: null,
     createdAt: "2026-05-01T08:00:00Z",
     revoked: false,
-    user: { id: "u1", username: "marc" },
+    user: { id: "u1", username: "testuser" },
   },
 ];
 
@@ -54,8 +54,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
@@ -107,7 +107,7 @@ describe("ApiTokenOverviewSection — responsive", () => {
     // All data points the desktop table shows must also appear in the
     // mobile cards. Token name + username + a permission badge + the
     // last-used/created labels are all present.
-    expect(html).toContain("marc"); // username
+    expect(html).toContain("testuser"); // username
     expect(html).toContain("iOS app"); // token name
     // F-19 (v1.4.19): the wildcard `*` permission renders as the
     // human-readable "All" with a tooltip explaining the semantics,
diff --git a/src/components/admin/__tests__/api-token-truncate.test.tsx b/src/components/admin/__tests__/api-token-truncate.test.tsx
index d01737bcb..5ad83c3be 100644
--- a/src/components/admin/__tests__/api-token-truncate.test.tsx
+++ b/src/components/admin/__tests__/api-token-truncate.test.tsx
@@ -4,7 +4,7 @@ import { renderToStaticMarkup } from "react-dom/server";
 /**
  * v1.4.19 A7 — `/admin/api-tokens` 4th-attempt scrollbar fix.
  *
- * the maintainer reported a "minimaler Scrollbar" still painting at the
+ * The maintainer reported a "minimaler Scrollbar" still painting at the
  * bottom-right of the api-tokens page, even after the v1.4.18 phase
  * A2 mobile-strip `no-scrollbar` fix. The remaining culprits are
  * inside the section card itself: long token names, long usernames,
@@ -37,7 +37,7 @@ const sampleTokens = [
     revoked: false,
     user: {
       id: "u1",
-      username: "marc-the-very-long-username-that-overflows",
+      username: "user-the-very-long-username-that-overflows",
     },
   },
 ];
@@ -62,8 +62,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
diff --git a/src/components/admin/__tests__/app-log-preview-summary-position.test.tsx b/src/components/admin/__tests__/app-log-preview-summary-position.test.tsx
index 9f0634861..be2894fe0 100644
--- a/src/components/admin/__tests__/app-log-preview-summary-position.test.tsx
+++ b/src/components/admin/__tests__/app-log-preview-summary-position.test.tsx
@@ -51,8 +51,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
diff --git a/src/components/admin/__tests__/backups-section-empty.test.tsx b/src/components/admin/__tests__/backups-section-empty.test.tsx
index fa8f81b3b..8029c7cf9 100644
--- a/src/components/admin/__tests__/backups-section-empty.test.tsx
+++ b/src/components/admin/__tests__/backups-section-empty.test.tsx
@@ -35,7 +35,7 @@ vi.mock("@tanstack/react-query", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "ADMIN" },
+    user: { id: "u1", username: "testuser", role: "ADMIN" },
     isAuthenticated: true,
     isLoading: false,
     refetch: vi.fn(),
diff --git a/src/components/admin/__tests__/coach-feedback-section.test.tsx b/src/components/admin/__tests__/coach-feedback-section.test.tsx
index 3d21af81b..a475ac91f 100644
--- a/src/components/admin/__tests__/coach-feedback-section.test.tsx
+++ b/src/components/admin/__tests__/coach-feedback-section.test.tsx
@@ -108,7 +108,7 @@ describe("CoachFeedbackSection", () => {
     expect(html).toContain('role="alert"');
   });
 
-  // v1.4.25 W8 regression — Marc reported a layout shift on
+  // v1.4.25 W8 regression — the maintainer reported a layout shift on
   // /admin/coach-feedback. Root cause was the title only rendering in the
   // empty + data branches, so the section grew taller (loading → data)
   // and snapped down. Lock the heading + outer-card structure across
diff --git a/src/components/admin/__tests__/login-overview-auth-filter.test.tsx b/src/components/admin/__tests__/login-overview-auth-filter.test.tsx
index cd52bcc5d..115800721 100644
--- a/src/components/admin/__tests__/login-overview-auth-filter.test.tsx
+++ b/src/components/admin/__tests__/login-overview-auth-filter.test.tsx
@@ -64,8 +64,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
diff --git a/src/components/admin/__tests__/login-overview-csv.test.ts b/src/components/admin/__tests__/login-overview-csv.test.ts
index c1e268813..ab31f02da 100644
--- a/src/components/admin/__tests__/login-overview-csv.test.ts
+++ b/src/components/admin/__tests__/login-overview-csv.test.ts
@@ -15,7 +15,7 @@ import { toCSV } from "@/lib/export";
  * `createdAt` string, which Excel/LibreOffice misread once the `Z`
  * suffix was stripped. This test pins:
  *
- *   - The column order Marc requested:
+ *   - The column order the maintainer requested:
  *     `timestamp → user → IP → location → provider → outcome` (email
  *     is absent from the audit-log API so it's intentionally skipped)
  *     followed by `action` + `details` for triage completeness.
@@ -80,7 +80,7 @@ function deterministicFormatter(iso: string): string {
 }
 
 describe("buildAuditLogCsvRecords", () => {
-  it("emits Marc's column order: timestamp → user → ip → location → provider → outcome (+ action, details)", () => {
+  it("emits the maintainer's column order: timestamp → user → ip → location → provider → outcome (+ action, details)", () => {
     const entries: AuditCsvEntry[] = [
       {
         createdAt: "2026-05-11T09:05:00.000Z",
@@ -88,7 +88,7 @@ describe("buildAuditLogCsvRecords", () => {
         ipAddress: "203.0.113.7",
         location: "Berlin, DE",
         details: null,
-        user: { id: "u1", username: "marc" },
+        user: { id: "u1", username: "testuser" },
       },
     ];
     const [record] = buildAuditLogCsvRecords(
@@ -119,7 +119,7 @@ describe("buildAuditLogCsvRecords", () => {
         ipAddress: null,
         location: null,
         details: null,
-        user: { id: "u1", username: "marc" },
+        user: { id: "u1", username: "testuser" },
       },
       {
         createdAt: "2026-05-11T09:06:00.000Z",
@@ -220,7 +220,7 @@ describe("toCSV(records, headerLabels) — audit-log integration", () => {
         ipAddress: "203.0.113.7",
         location: "Berlin, DE",
         details: null,
-        user: { id: "u1", username: "marc" },
+        user: { id: "u1", username: "testuser" },
       },
     ];
     const records = buildAuditLogCsvRecords(
@@ -234,12 +234,12 @@ describe("toCSV(records, headerLabels) — audit-log integration", () => {
       "Zeitpunkt,Benutzer,IP,Standort,Mobilfunkanbieter,Anbieter,Ergebnis,Aktion,Details",
     );
     expect(lines[1]).toBe(
-      '2026-05-11T09:05:00+00:00,marc,203.0.113.7,"Berlin, DE",,Passkey,Erfolgreich,auth.login.passkey,',
+      '2026-05-11T09:05:00+00:00,testuser,203.0.113.7,"Berlin, DE",,Passkey,Erfolgreich,auth.login.passkey,',
     );
   });
 
   it("folds the GeoLite2 organisation string to the short DACH carrier label", () => {
-    // Marc's spec: the verbose MMDB org strings get a glanceable chip.
+    // The maintainer's spec: the verbose MMDB org strings get a glanceable chip.
     // The CSV column carries the same folded text so a downstream
     // spreadsheet matches what the admin overview screen renders.
     const entries: AuditCsvEntry[] = [
@@ -251,7 +251,7 @@ describe("toCSV(records, headerLabels) — audit-log integration", () => {
         carrier: "Deutsche Telekom AG",
         asn: 3320,
         details: null,
-        user: { id: "u1", username: "marc" },
+        user: { id: "u1", username: "testuser" },
       },
       {
         createdAt: "2026-05-11T09:06:00.000Z",
@@ -261,7 +261,7 @@ describe("toCSV(records, headerLabels) — audit-log integration", () => {
         carrier: "Vodafone GmbH",
         asn: 3209,
         details: null,
-        user: { id: "u2", username: "marc" },
+        user: { id: "u2", username: "testuser" },
       },
       {
         createdAt: "2026-05-11T09:07:00.000Z",
@@ -271,7 +271,7 @@ describe("toCSV(records, headerLabels) — audit-log integration", () => {
         carrier: "1&1 Versatel GmbH",
         asn: 8881,
         details: null,
-        user: { id: "u3", username: "marc" },
+        user: { id: "u3", username: "testuser" },
       },
       {
         createdAt: "2026-05-11T09:08:00.000Z",
@@ -281,7 +281,7 @@ describe("toCSV(records, headerLabels) — audit-log integration", () => {
         carrier: "Telefónica Germany GmbH & Co. OHG",
         asn: 6805,
         details: null,
-        user: { id: "u4", username: "marc" },
+        user: { id: "u4", username: "testuser" },
       },
       {
         createdAt: "2026-05-11T09:09:00.000Z",
@@ -291,7 +291,7 @@ describe("toCSV(records, headerLabels) — audit-log integration", () => {
         carrier: "Google LLC",
         asn: 15169,
         details: null,
-        user: { id: "u5", username: "marc" },
+        user: { id: "u5", username: "testuser" },
       },
     ];
     const records = buildAuditLogCsvRecords(
diff --git a/src/components/admin/__tests__/login-overview-no-collapse.test.tsx b/src/components/admin/__tests__/login-overview-no-collapse.test.tsx
index ceb0488a3..56311bdc1 100644
--- a/src/components/admin/__tests__/login-overview-no-collapse.test.tsx
+++ b/src/components/admin/__tests__/login-overview-no-collapse.test.tsx
@@ -37,8 +37,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
       timezone: "Europe/Berlin",
     },
diff --git a/src/components/admin/__tests__/login-overview-pagination-position.test.tsx b/src/components/admin/__tests__/login-overview-pagination-position.test.tsx
index 2950e2098..e5e7721d6 100644
--- a/src/components/admin/__tests__/login-overview-pagination-position.test.tsx
+++ b/src/components/admin/__tests__/login-overview-pagination-position.test.tsx
@@ -23,7 +23,7 @@ vi.mock("next/navigation", () => ({
 const sampleEntries = [
   {
     id: "ev-1",
-    user: { id: "u1", username: "marc" },
+    user: { id: "u1", username: "testuser" },
     action: "auth.login.success",
     ipAddress: "203.0.113.10",
     location: "Berlin, DE",
@@ -55,8 +55,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
       timezone: "Europe/Berlin",
     },
diff --git a/src/components/admin/__tests__/login-overview-provider.test.tsx b/src/components/admin/__tests__/login-overview-provider.test.tsx
index 74994143f..c24af0fbf 100644
--- a/src/components/admin/__tests__/login-overview-provider.test.tsx
+++ b/src/components/admin/__tests__/login-overview-provider.test.tsx
@@ -55,7 +55,7 @@ describe("providerForAction", () => {
 
 describe("iconForAuthProvider", () => {
   it("maps each provider to the documented lucide glyph", () => {
-    // Marc's brief pinned the exact icon for each provider so the
+    // The maintainer's brief pinned the exact icon for each provider so the
     // visual language stays consistent across the admin surface.
     expect(iconForAuthProvider("password")).toBe(KeyRound);
     expect(iconForAuthProvider("passkey")).toBe(Fingerprint);
diff --git a/src/components/admin/__tests__/sections.test.tsx b/src/components/admin/__tests__/sections.test.tsx
index c12e7916b..4127ed94c 100644
--- a/src/components/admin/__tests__/sections.test.tsx
+++ b/src/components/admin/__tests__/sections.test.tsx
@@ -30,8 +30,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
@@ -149,7 +149,7 @@ describe("admin sections — SSR smoke", () => {
   it("<AiQualitySection> renders the empty-state when no summary exists", () => {
     const html = render(<AiQualitySection />);
     // v1.4.33 IW7 — section renamed from "AI Quality" to
-    // "Insights Quality" per the Marc-Voice rule (no "KI"/"AI" prefix
+    // "Insights Quality" per the project-voice rule (no "KI"/"AI" prefix
     // in user-facing copy).
     expect(html).toContain("Insights Quality");
     expect(html).toContain("No feedback yet");
diff --git a/src/components/admin/__tests__/status-card-grid.test.tsx b/src/components/admin/__tests__/status-card-grid.test.tsx
index 6d34550c6..1a8029bd9 100644
--- a/src/components/admin/__tests__/status-card-grid.test.tsx
+++ b/src/components/admin/__tests__/status-card-grid.test.tsx
@@ -37,8 +37,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
@@ -74,8 +74,8 @@ describe("/admin overview composition", () => {
   it("renders the welcome card with the admin's username", () => {
     const html = render(<AdminOverviewPage />);
     // `welcomeTitle` interpolates the username; the mocked auth hook
-    // returns "marc".
-    expect(html).toContain("Welcome, marc");
+    // returns "testuser".
+    expect(html).toContain("Welcome, testuser");
     expect(html).toContain("admin-overview-welcome-heading");
   });
 
diff --git a/src/components/admin/__tests__/user-management-empty.test.tsx b/src/components/admin/__tests__/user-management-empty.test.tsx
index e40f4c5cb..9fc59977b 100644
--- a/src/components/admin/__tests__/user-management-empty.test.tsx
+++ b/src/components/admin/__tests__/user-management-empty.test.tsx
@@ -41,8 +41,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
diff --git a/src/components/admin/__tests__/user-management-responsive.test.tsx b/src/components/admin/__tests__/user-management-responsive.test.tsx
index 76837f560..cdcc955f9 100644
--- a/src/components/admin/__tests__/user-management-responsive.test.tsx
+++ b/src/components/admin/__tests__/user-management-responsive.test.tsx
@@ -25,8 +25,8 @@ vi.mock("next/navigation", () => ({
 const sampleUsers = [
   {
     id: "u1",
-    username: "marc",
-    email: "marc@example.com",
+    username: "testuser",
+    email: "user@example.com",
     role: "ADMIN" as const,
     passkeyCount: 2,
     createdAt: "2026-04-01T08:00:00Z",
@@ -57,8 +57,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "ADMIN",
     },
     isAuthenticated: true,
diff --git a/src/components/admin/_shared.tsx b/src/components/admin/_shared.tsx
index 975da512e..14ae3aa41 100644
--- a/src/components/admin/_shared.tsx
+++ b/src/components/admin/_shared.tsx
@@ -8,6 +8,7 @@ import { Switch } from "@/components/ui/switch";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { PasswordInput as SharedPasswordInput } from "@/components/ui/password-input";
+import { apiGet, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * Re-export the canonical password input so admin sections have access to
@@ -228,9 +229,7 @@ export function useAdminSettings() {
   return useQuery({
     queryKey: queryKeys.adminSettings(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/settings");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as AdminSettings;
+      return apiGet<AdminSettings>("/api/admin/settings");
     },
   });
 }
@@ -240,14 +239,7 @@ export function useUpdateSettings() {
   const { t } = useTranslations();
   return useMutation({
     mutationFn: async (data: Record<string, unknown>) => {
-      const res = await fetch("/api/admin/settings", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(data),
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
+      await apiPut("/api/admin/settings", data);
     },
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: queryKeys.adminSettings() });
@@ -423,7 +415,7 @@ export function carrierShortLabel(rawAsnOrg: string): string {
  *
  * Pulled out of the section component so the column order, header
  * mapping, and provider/outcome derivation are reachable from a
- * pure unit test without rendering the React tree. Marc's spec pins
+ * pure unit test without rendering the React tree. The maintainer's spec pins
  * the column order at `timestamp → user → IP → location → provider
  * → outcome` (email is absent from the audit-log API and would
  * require schema/API changes that are out of scope). `action` and
@@ -526,9 +518,7 @@ export function useSystemStatus() {
   return useQuery({
     queryKey: queryKeys.adminStatus(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/status");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as SystemStatus;
+      return apiGet<SystemStatus>("/api/admin/status");
     },
   });
 }
@@ -554,9 +544,7 @@ export function usePublicVersion() {
   return useQuery({
     queryKey: queryKeys.publicVersion(),
     queryFn: async () => {
-      const res = await fetch("/api/version");
-      if (!res.ok) throw new Error("Failed to load version");
-      return (await res.json()).data as PublicVersion;
+      return apiGet<PublicVersion>("/api/version");
     },
     staleTime: 5 * 60_000,
   });
diff --git a/src/components/admin/ai-quality-section.tsx b/src/components/admin/ai-quality-section.tsx
index 2233c9c36..8529eb18a 100644
--- a/src/components/admin/ai-quality-section.tsx
+++ b/src/components/admin/ai-quality-section.tsx
@@ -23,6 +23,7 @@ import { useQuery } from "@tanstack/react-query";
 import { Sparkles, Loader2 } from "lucide-react";
 import { useTranslations, useFormatters } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { helpfulRateColour } from "./_shared";
 
 interface FeedbackBucket {
@@ -42,11 +43,6 @@ interface FeedbackSummary {
   buckets: FeedbackBucket[];
 }
 
-interface AiQualityResponse {
-  data: { summary: FeedbackSummary | null } | null;
-  error?: string | null;
-}
-
 const SEVERITY_TINT: Record<string, string> = {
   info: "text-dracula-cyan",
   suggestion: "text-dracula-purple",
@@ -61,10 +57,10 @@ export function AiQualitySection() {
   const query = useQuery({
     queryKey: queryKeys.adminAiQuality(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/ai-quality");
-      const json = (await res.json()) as AiQualityResponse;
-      if (!res.ok) throw new Error(json.error ?? "ai_quality_failed");
-      return json.data?.summary ?? null;
+      const data = await apiGet<{ summary: FeedbackSummary | null } | null>(
+        "/api/admin/ai-quality",
+      );
+      return data?.summary ?? null;
     },
   });
 
diff --git a/src/components/admin/api-token-overview-section.tsx b/src/components/admin/api-token-overview-section.tsx
index 0f666696f..66631e0b6 100644
--- a/src/components/admin/api-token-overview-section.tsx
+++ b/src/components/admin/api-token-overview-section.tsx
@@ -14,6 +14,7 @@ import { formatDate, formatDateTime } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { type ApiTokenInfo } from "./_shared";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * Wraps a string in `truncate` + tooltip so a long token name /
@@ -21,7 +22,7 @@ import { type ApiTokenInfo } from "./_shared";
  *
  * v1.4.19 phase A7 (4th attempt) — earlier fixes (column-hide,
  * mobile card-list, mobile-strip `no-scrollbar`) cleared every
- * scrollbar the maintainer reported except a residual painted bar he kept
+ * scrollbar the maintainer reported except a residual painted bar they kept
  * seeing at the bottom-right. Production probe confirmed no
  * remaining horizontal-overflow culprits, but the cards still
  * carried `break-all` next to `truncate` (dead code; `white-space:
@@ -150,9 +151,7 @@ export function ApiTokenOverviewSection() {
   const { data: tokens, isLoading } = useQuery({
     queryKey: queryKeys.adminTokens(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/tokens");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as ApiTokenInfo[];
+      return apiGet<ApiTokenInfo[]>("/api/admin/tokens");
     },
   });
 
diff --git a/src/components/admin/app-log-preview-section.tsx b/src/components/admin/app-log-preview-section.tsx
index 201a7c43f..84d71c62d 100644
--- a/src/components/admin/app-log-preview-section.tsx
+++ b/src/components/admin/app-log-preview-section.tsx
@@ -49,6 +49,7 @@ import { formatDateTime } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import type { WideEvent, LogLevel } from "@/lib/logging/types";
+import { apiGet } from "@/lib/api/api-fetch";
 
 type RangePreset = "15m" | "1h" | "6h" | "all";
 
@@ -103,9 +104,7 @@ export function AppLogPreviewSection() {
   const { data, isLoading, refetch, isFetching } = useQuery({
     queryKey: queryKeys.adminAppLogs(traceId, actionFilter, level, range),
     queryFn: async () => {
-      const res = await fetch(`/api/admin/app-logs?${params.toString()}`);
-      if (!res.ok) throw new Error("Failed to load app logs");
-      return (await res.json()).data as AppLogsResponse;
+      return apiGet<AppLogsResponse>(`/api/admin/app-logs?${params.toString()}`);
     },
     refetchInterval: 30_000,
   });
diff --git a/src/components/admin/assistant-section.tsx b/src/components/admin/assistant-section.tsx
index 21c05552b..a58743d80 100644
--- a/src/components/admin/assistant-section.tsx
+++ b/src/components/admin/assistant-section.tsx
@@ -6,7 +6,8 @@ import { toast } from "sonner";
 
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
-import { SettingsToggle, getApiErrorMessage } from "./_shared";
+import { SettingsToggle } from "./_shared";
+import { apiGet, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.31 — operator-side panel for the six assistant feature
@@ -48,9 +49,7 @@ function useAssistantFlags() {
   return useQuery({
     queryKey: queryKeys.adminAssistantFlags(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/settings/assistant-flags");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as AssistantFlagsResponse;
+      return apiGet<AssistantFlagsResponse>("/api/admin/settings/assistant-flags");
     },
   });
 }
@@ -62,15 +61,7 @@ function useUpdateAssistantFlags() {
     mutationFn: async (
       patch: Partial<AssistantFlagsResponse["raw"]>,
     ): Promise<AssistantFlagsResponse> => {
-      const res = await fetch("/api/admin/settings/assistant-flags", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(patch),
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      return (await res.json()).data as AssistantFlagsResponse;
+      return apiPut<AssistantFlagsResponse>("/api/admin/settings/assistant-flags", patch);
     },
     onSuccess: (data) => {
       client.setQueryData(
diff --git a/src/components/admin/backups-section.tsx b/src/components/admin/backups-section.tsx
index ba941a5ff..312d78910 100644
--- a/src/components/admin/backups-section.tsx
+++ b/src/components/admin/backups-section.tsx
@@ -44,6 +44,7 @@ import { useFormatters, useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import type { BackupRow, BackupsList } from "@/types/backups";
 import { getApiErrorMessage } from "./_shared";
+import { apiFetch, apiFetchRaw, apiGet, apiPost } from "@/lib/api/api-fetch";
 
 /**
  * Typed-confirmation dialog for restore. The destructive Restore button
@@ -175,19 +176,13 @@ export function BackupsSection() {
   const { data, isLoading, isError } = useQuery({
     queryKey: queryKeys.adminBackups(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/backups");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as BackupsList;
+      return apiGet<BackupsList>("/api/admin/backups");
     },
   });
 
   const runBackup = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/admin/backups/run", { method: "POST" });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      return (await res.json()).data as { jobId: string | null };
+      return apiPost<{ jobId: string | null }>("/api/admin/backups/run");
     },
     onSuccess: () => {
       toast.success(t("admin.section.backups.runEnqueued"));
@@ -219,14 +214,9 @@ export function BackupsSection() {
     mutationFn: async (file: File) => {
       const fd = new FormData();
       fd.append("file", file);
-      const res = await fetch("/api/admin/backups/upload", {
-        method: "POST",
-        body: fd,
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      return (await res.json()).data as {
+      // apiFetch with a raw init: the multipart body must NOT be JSON
+      // re-encoded, so the verb helper (which JSON-stringifies) is out.
+      return apiFetch<{
         id: string;
         valid: true;
         summary: {
@@ -237,7 +227,7 @@ export function BackupsSection() {
           cycles?: number;
           cycleDayLogs?: number;
         };
-      };
+      }>("/api/admin/backups/upload", { method: "POST", body: fd });
     },
     onSuccess: (data) => {
       const total =
@@ -280,18 +270,11 @@ export function BackupsSection() {
       // destructive transaction. Include the row id so two different
       // backups can both be restored independently in the same minute.
       const idempotencyKey = `restore-${row.id}-${crypto.randomUUID()}`;
-      const res = await fetch(`/api/admin/backups/${row.id}/restore`, {
-        method: "POST",
-        headers: {
-          "Content-Type": "application/json",
-          "Idempotency-Key": idempotencyKey,
-        },
-        body: JSON.stringify({ confirm: "RESTORE" }),
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      return (await res.json()).data as { restored: true };
+      return apiPost<{ restored: true }>(
+        `/api/admin/backups/${row.id}/restore`,
+        { confirm: "RESTORE" },
+        { headers: { "Idempotency-Key": idempotencyKey } },
+      );
     },
     onSuccess: () => {
       toast.success(t("admin.section.backups.restoreSuccess"));
@@ -312,7 +295,9 @@ export function BackupsSection() {
   async function handleDownload(row: BackupRow) {
     setDownloadingId(row.id);
     try {
-      const res = await fetch(`/api/admin/backups/${row.id}/download`);
+      // apiFetchRaw: the download needs the raw Response for the blob +
+      // the Content-Disposition filename header.
+      const res = await apiFetchRaw(`/api/admin/backups/${row.id}/download`);
       if (!res.ok) {
         throw new Error(await getApiErrorMessage(res));
       }
diff --git a/src/components/admin/coach-feedback-section.tsx b/src/components/admin/coach-feedback-section.tsx
index 55cc42bbb..26e9a3cd0 100644
--- a/src/components/admin/coach-feedback-section.tsx
+++ b/src/components/admin/coach-feedback-section.tsx
@@ -23,6 +23,7 @@ import { Loader2, Sparkles } from "lucide-react";
 
 import { useTranslations, useFormatters } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { helpfulRateColour } from "./_shared";
 
 interface CoachFeedbackBucket {
@@ -41,11 +42,6 @@ interface FeedbackSummary {
   coachBuckets?: CoachFeedbackBucket[];
 }
 
-interface CoachFeedbackResponse {
-  data: { summary: FeedbackSummary | null } | null;
-  error?: string | null;
-}
-
 export function CoachFeedbackSection() {
   const { t } = useTranslations();
   const fmt = useFormatters();
@@ -53,10 +49,10 @@ export function CoachFeedbackSection() {
   const query = useQuery({
     queryKey: queryKeys.adminCoachFeedback(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/ai-quality");
-      const json = (await res.json()) as CoachFeedbackResponse;
-      if (!res.ok) throw new Error(json.error ?? "coach_feedback_failed");
-      return json.data?.summary ?? null;
+      const data = await apiGet<{ summary: FeedbackSummary | null } | null>(
+        "/api/admin/ai-quality",
+      );
+      return data?.summary ?? null;
     },
   });
 
@@ -69,7 +65,7 @@ export function CoachFeedbackSection() {
   // baseline stays at a constant Y-offset. Previously the loading branch
   // returned a thin flex-row stub and the error branch a p-4 alert with
   // NO heading, which made the entire section snap downward when the
-  // fetched data resolved — Marc reported the visible layout shift on
+  // fetched data resolved — the maintainer reported the visible layout shift on
   // /admin/coach-feedback. Mirrors the canonical structure used by
   // <SystemStatusSection> (header outside the fetch-state branch).
   return (
diff --git a/src/components/admin/danger-zone-section.tsx b/src/components/admin/danger-zone-section.tsx
index f2bd8914a..41983cf92 100644
--- a/src/components/admin/danger-zone-section.tsx
+++ b/src/components/admin/danger-zone-section.tsx
@@ -16,6 +16,7 @@ import {
 } from "@/components/ui/alert-dialog";
 import { Button } from "@/components/ui/button";
 import { useTranslations } from "@/lib/i18n/context";
+import { apiDelete } from "@/lib/api/api-fetch";
 
 export function DangerZoneSection() {
   const { t } = useTranslations();
@@ -24,14 +25,7 @@ export function DangerZoneSection() {
 
   const wipeAllData = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/admin/data", {
-        method: "DELETE",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ confirm: "DELETE ALL" }),
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("common.error"));
-      return json.data as {
+      return apiDelete<{
         measurements: number;
         intakeEvents: number;
         medications: number;
@@ -41,7 +35,7 @@ export function DangerZoneSection() {
         notificationChannels: number;
         pushSubscriptions: number;
         telegramScheduledDeletions: number;
-      };
+      }>("/api/admin/data", { confirm: "DELETE ALL" });
     },
     onSuccess: (data) => {
       queryClient.invalidateQueries();
diff --git a/src/components/admin/feedback-inbox-section.tsx b/src/components/admin/feedback-inbox-section.tsx
index fb28780b9..cbda34295 100644
--- a/src/components/admin/feedback-inbox-section.tsx
+++ b/src/components/admin/feedback-inbox-section.tsx
@@ -38,9 +38,9 @@ import {
   type FeedbackItem,
   type FeedbackListResponse,
   type FeedbackStatusType,
-  getApiErrorMessage,
   useSystemStatus,
 } from "./_shared";
+import { apiDelete, apiGet, apiPatch, apiPost } from "@/lib/api/api-fetch";
 
 export function FeedbackInboxSection() {
   const { t } = useTranslations();
@@ -54,11 +54,7 @@ export function FeedbackInboxSection() {
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.adminFeedback(activeStatus),
     queryFn: async () => {
-      const res = await fetch(
-        `/api/admin/feedback?status=${activeStatus}&limit=100`,
-      );
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as FeedbackListResponse;
+      return apiGet<FeedbackListResponse>(`/api/admin/feedback?status=${activeStatus}&limit=100`);
     },
   });
 
@@ -259,12 +255,7 @@ function FeedbackDetailDialog({
       status?: FeedbackStatusType;
       adminNote?: string | null;
     }) => {
-      const res = await fetch(`/api/admin/feedback/${item.id}`, {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(payload),
-      });
-      if (!res.ok) throw new Error(await getApiErrorMessage(res));
+      await apiPatch(`/api/admin/feedback/${item.id}`, payload);
     },
     onSuccess: (_, vars) => {
       onMutated();
@@ -281,10 +272,7 @@ function FeedbackDetailDialog({
 
   const archive = useMutation({
     mutationFn: async () => {
-      const res = await fetch(`/api/admin/feedback/${item.id}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) throw new Error(await getApiErrorMessage(res));
+      await apiDelete(`/api/admin/feedback/${item.id}`);
     },
     onSuccess: () => {
       onMutated();
@@ -299,11 +287,7 @@ function FeedbackDetailDialog({
 
   const publish = useMutation({
     mutationFn: async () => {
-      const res = await fetch(`/api/admin/feedback/${item.id}/github`, {
-        method: "POST",
-      });
-      if (!res.ok) throw new Error(await getApiErrorMessage(res));
-      return (await res.json()).data as { issueUrl: string };
+      return apiPost<{ issueUrl: string }>(`/api/admin/feedback/${item.id}/github`);
     },
     onSuccess: (data) => {
       setIssueUrl(data.issueUrl);
diff --git a/src/components/admin/glitchtip-section.tsx b/src/components/admin/glitchtip-section.tsx
index 37760e572..6b141f589 100644
--- a/src/components/admin/glitchtip-section.tsx
+++ b/src/components/admin/glitchtip-section.tsx
@@ -11,10 +11,10 @@ import { Label } from "@/components/ui/label";
 import { useTranslations } from "@/lib/i18n/context";
 import {
   SettingsToggle,
-  getApiErrorMessage,
   useAdminSettings,
   useUpdateSettings,
 } from "./_shared";
+import { apiPost } from "@/lib/api/api-fetch";
 
 export function GlitchtipSection() {
   const { t } = useTranslations();
@@ -35,14 +35,10 @@ export function GlitchtipSection() {
 
   const testGlitchtip = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/admin/monitoring/glitchtip-test", {
-        method: "POST",
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      const json = (await res.json()) as { data?: { message?: string } };
-      return json.data?.message ?? t("admin.monitoringTestSuccess");
+      const data = await apiPost<{ message?: string } | undefined>(
+        "/api/admin/monitoring/glitchtip-test",
+      );
+      return data?.message ?? t("admin.monitoringTestSuccess");
     },
     onSuccess: (message) => {
       toast.success(message);
diff --git a/src/components/admin/host-metrics-chart.tsx b/src/components/admin/host-metrics-chart.tsx
index 5fd1625f2..7188f90f3 100644
--- a/src/components/admin/host-metrics-chart.tsx
+++ b/src/components/admin/host-metrics-chart.tsx
@@ -39,6 +39,7 @@ import { useMemo } from "react";
 import { useFormatters, useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { Skeleton } from "@/components/ui/skeleton";
+import { apiGet } from "@/lib/api/api-fetch";
 
 interface HostMetricsApiSample {
   capturedAt: string;
@@ -134,9 +135,7 @@ export function HostMetricsChart() {
   const { data, isLoading, isError } = useQuery({
     queryKey: queryKeys.adminHostMetrics("2h"),
     queryFn: async () => {
-      const res = await fetch("/api/admin/host-metrics?since=2h");
-      if (!res.ok) throw new Error("Failed to load host metrics");
-      return (await res.json()).data as HostMetricsApiResponse;
+      return apiGet<HostMetricsApiResponse>("/api/admin/host-metrics?since=2h");
     },
     // 60s matches the sampler cadence — anything faster would just
     // re-render the same data.
diff --git a/src/components/admin/invite-tokens-section.tsx b/src/components/admin/invite-tokens-section.tsx
index 8b38990c9..67b27dbfe 100644
--- a/src/components/admin/invite-tokens-section.tsx
+++ b/src/components/admin/invite-tokens-section.tsx
@@ -79,6 +79,7 @@ import { formatDate, formatDateTime } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { cn } from "@/lib/utils";
+import { apiDelete, apiGet, apiPost } from "@/lib/api/api-fetch";
 
 interface InviteRedemptionEntry {
   id: string;
@@ -187,9 +188,7 @@ export function InviteTokensSection() {
   const { data: invites, isError } = useQuery({
     queryKey: queryKeys.adminInvites(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/invites");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as AdminInvite[];
+      return apiGet<AdminInvite[]>("/api/admin/invites");
     },
   });
 
@@ -199,13 +198,10 @@ export function InviteTokensSection() {
       expiresInDays: number;
       maxUses: number;
     }): Promise<MintedInvite> => {
-      const res = await fetch("/api/admin/invites", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(input),
-      });
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-      const data = (await res.json()).data as Omit<MintedInvite, "qrDataUrl">;
+      const data = await apiPost<Omit<MintedInvite, "qrDataUrl">>(
+        "/api/admin/invites",
+        input,
+      );
       // Lazy chunk: qrcode is only ever needed right here, at mint time.
       const QRCode = (await import("qrcode")).default;
       const qrDataUrl = await QRCode.toDataURL(data.url, {
@@ -226,10 +222,7 @@ export function InviteTokensSection() {
 
   const revoke = useMutation({
     mutationFn: async (id: string) => {
-      const res = await fetch(`/api/admin/invites/${id}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
+      await apiDelete(`/api/admin/invites/${id}`);
     },
     onSuccess: () => {
       toast.success(t("admin.invites.revokedToast"));
@@ -549,6 +542,16 @@ export function InviteTokensSection() {
                   {t("admin.invites.createDescription")}
                 </DialogDescription>
               </DialogHeader>
+              {/* v1.16.4 — a real form so Enter in the max-uses field
+                  submits; mirrors the intake-edit dialog convention. */}
+              <form
+                onSubmit={(e) => {
+                  e.preventDefault();
+                  if (create.isPending) return;
+                  submitCreate();
+                }}
+                className="space-y-4"
+              >
               <div className="space-y-5">
                 <fieldset>
                   <legend className="text-sm font-medium">
@@ -600,9 +603,9 @@ export function InviteTokensSection() {
               </div>
               <DialogFooter>
                 <Button
-                  type="button"
+                  type="submit"
                   disabled={create.isPending}
-                  onClick={submitCreate}
+                  aria-busy={create.isPending || undefined}
                   data-testid="admin-invites-submit-create"
                 >
                   {create.isPending ? (
@@ -616,6 +619,7 @@ export function InviteTokensSection() {
                   {t("admin.invites.createConfirm")}
                 </Button>
               </DialogFooter>
+              </form>
             </>
           ) : (
             <>
diff --git a/src/components/admin/login-overview-section.tsx b/src/components/admin/login-overview-section.tsx
index 98b241027..a31532966 100644
--- a/src/components/admin/login-overview-section.tsx
+++ b/src/components/admin/login-overview-section.tsx
@@ -36,6 +36,7 @@ import {
   useAuthActionLabels,
   useAuthProviderLabels,
 } from "./_shared";
+import { apiGet } from "@/lib/api/api-fetch";
 
 type DateRangePreset = "all" | "24h" | "7d" | "30d";
 type PerPageValue = 25 | 50 | 100;
@@ -130,9 +131,7 @@ export function LoginOverviewSection() {
       if (filter === "failed") {
         params.set("action", "auth.login.failed");
       }
-      const res = await fetch(`/api/admin/audit-log?${params.toString()}`);
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as AuditLogResponse;
+      return apiGet<AuditLogResponse>(`/api/admin/audit-log?${params.toString()}`);
     },
   });
 
@@ -140,9 +139,7 @@ export function LoginOverviewSection() {
   const { data: actionsData } = useQuery({
     queryKey: queryKeys.adminAuditActions(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/audit-log/actions");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as { actions: string[] };
+      return apiGet<{ actions: string[] }>("/api/admin/audit-log/actions");
     },
     staleTime: 5 * 60_000,
   });
diff --git a/src/components/admin/recent-audit-preview.tsx b/src/components/admin/recent-audit-preview.tsx
index 8da02a6e2..138e223c0 100644
--- a/src/components/admin/recent-audit-preview.tsx
+++ b/src/components/admin/recent-audit-preview.tsx
@@ -23,6 +23,7 @@ import { formatDateTime } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { type AdminAuditEntry, useAuthActionLabels } from "./_shared";
+import { apiGet } from "@/lib/api/api-fetch";
 
 const PREVIEW_LIMIT = 10;
 
@@ -37,11 +38,7 @@ export function RecentAuditPreview() {
   const { data, isLoading, isError } = useQuery({
     queryKey: queryKeys.adminAuditOverview(),
     queryFn: async () => {
-      const res = await fetch(
-        `/api/admin/audit-log?limit=${PREVIEW_LIMIT}&filter=auth`,
-      );
-      if (!res.ok) throw new Error("Failed to load audit log");
-      return (await res.json()).data as AuditLogResponse;
+      return apiGet<AuditLogResponse>(`/api/admin/audit-log?limit=${PREVIEW_LIMIT}&filter=auth`);
     },
     // Avoid hitting the DB on every page focus; the overview is the
     // type of page admins keep open and re-render frequently.
diff --git a/src/components/admin/reminders-section.tsx b/src/components/admin/reminders-section.tsx
index fb70be8e3..a097a32a1 100644
--- a/src/components/admin/reminders-section.tsx
+++ b/src/components/admin/reminders-section.tsx
@@ -9,11 +9,8 @@ import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { useTranslations } from "@/lib/i18n/context";
-import {
-  getApiErrorMessage,
-  useAdminSettings,
-  useUpdateSettings,
-} from "./_shared";
+import { useAdminSettings, useUpdateSettings } from "./_shared";
+import { apiPost } from "@/lib/api/api-fetch";
 
 export function RemindersSection() {
   const { t } = useTranslations();
@@ -28,23 +25,17 @@ export function RemindersSection() {
 
   const testNotification = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/admin/notifications/test", {
-        method: "POST",
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      const json = (await res.json()) as {
-        data?: {
-          message?: string;
-          results?: Array<{
-            channel: string;
-            success: boolean;
-            error?: string;
-          }>;
-        };
-      };
-      return json.data;
+      return apiPost<
+        | {
+            message?: string;
+            results?: Array<{
+              channel: string;
+              success: boolean;
+              error?: string;
+            }>;
+          }
+        | undefined
+      >("/api/admin/notifications/test");
     },
     onSuccess: (data) => {
       const hasFailures = data?.results?.some((r) => !r.success);
@@ -65,35 +56,29 @@ export function RemindersSection() {
 
   const reminderCheck = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/admin/notifications/reminder-check", {
-        method: "POST",
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      const json = (await res.json()) as {
-        data?: {
-          message?: string;
-          medications?: Array<{
-            name: string;
-            dose: string;
-            user: string;
-            localTime: string;
-            dayOfWeek: string;
-            notificationsEnabled: boolean;
-            schedules: Array<{
-              window: string;
-              days: string;
-              status: string;
-              label: string;
-              notificationSent?: boolean;
+      return apiPost<
+        | {
+            message?: string;
+            medications?: Array<{
+              name: string;
+              dose: string;
+              user: string;
+              localTime: string;
+              dayOfWeek: string;
+              notificationsEnabled: boolean;
+              schedules: Array<{
+                window: string;
+                days: string;
+                status: string;
+                label: string;
+                notificationSent?: boolean;
+              }>;
+              eventsToday: number;
             }>;
-            eventsToday: number;
-          }>;
-          notificationsSent?: number;
-        };
-      };
-      return json.data;
+            notificationsSent?: number;
+          }
+        | undefined
+      >("/api/admin/notifications/reminder-check");
     },
     onSuccess: (data) => {
       toast.success(data?.message ?? t("admin.reminderCheckSuccess"));
diff --git a/src/components/admin/umami-section.tsx b/src/components/admin/umami-section.tsx
index 7fa27a4f5..825519fc8 100644
--- a/src/components/admin/umami-section.tsx
+++ b/src/components/admin/umami-section.tsx
@@ -11,10 +11,10 @@ import { Label } from "@/components/ui/label";
 import { useTranslations } from "@/lib/i18n/context";
 import {
   SettingsToggle,
-  getApiErrorMessage,
   useAdminSettings,
   useUpdateSettings,
 } from "./_shared";
+import { apiPost } from "@/lib/api/api-fetch";
 
 export function UmamiSection() {
   const { t } = useTranslations();
@@ -38,14 +38,10 @@ export function UmamiSection() {
 
   const testUmami = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/admin/monitoring/umami-test", {
-        method: "POST",
-      });
-      if (!res.ok) {
-        throw new Error(await getApiErrorMessage(res));
-      }
-      const json = (await res.json()) as { data?: { message?: string } };
-      return json.data?.message ?? t("admin.monitoringTestSuccess");
+      const data = await apiPost<{ message?: string } | undefined>(
+        "/api/admin/monitoring/umami-test",
+      );
+      return data?.message ?? t("admin.monitoringTestSuccess");
     },
     onSuccess: (message) => {
       toast.success(message);
diff --git a/src/components/admin/user-management-section.tsx b/src/components/admin/user-management-section.tsx
index fc14b215d..44fe1bc60 100644
--- a/src/components/admin/user-management-section.tsx
+++ b/src/components/admin/user-management-section.tsx
@@ -25,6 +25,7 @@ import { formatDate } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { type AdminUser, PasswordInput } from "./_shared";
+import { apiGet, apiPost, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * Filter values for the v1.5 users sub-route. The User model does NOT
@@ -52,9 +53,7 @@ export function UserManagementSection() {
   const { data: users } = useQuery({
     queryKey: queryKeys.adminUsers(),
     queryFn: async () => {
-      const res = await fetch("/api/admin/users");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as AdminUser[];
+      return apiGet<AdminUser[]>("/api/admin/users");
     },
   });
 
@@ -73,13 +72,7 @@ export function UserManagementSection() {
       id: string;
       data: Record<string, unknown>;
     }) => {
-      const res = await fetch(`/api/admin/users/${id}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(data),
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("common.error"));
+      await apiPut(`/api/admin/users/${id}`, data);
     },
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: queryKeys.adminUsers() });
@@ -97,13 +90,7 @@ export function UserManagementSection() {
 
   const resetPw = useMutation({
     mutationFn: async ({ id, password }: { id: string; password: string }) => {
-      const res = await fetch(`/api/admin/users/${id}/reset-password`, {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ password }),
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("common.error"));
+      await apiPost(`/api/admin/users/${id}/reset-password`, { password });
     },
     onSuccess: () => {
       setResetMsg(t("admin.passwordReset"));
@@ -116,12 +103,9 @@ export function UserManagementSection() {
 
   const forceLogout = useMutation({
     mutationFn: async ({ id }: { id: string }) => {
-      const res = await fetch(`/api/admin/users/${id}/force-logout`, {
-        method: "POST",
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("common.error"));
-      return json.data as { sessionsRevoked: number };
+      return apiPost<{ sessionsRevoked: number }>(
+        `/api/admin/users/${id}/force-logout`,
+      );
     },
     onSuccess: (result, vars) => {
       const username =
@@ -421,7 +405,22 @@ export function UserManagementSection() {
           <h3 className="mb-3 text-sm font-semibold">
             {t("admin.editUserTitle", { name: editingUser.username })}
           </h3>
-          <div className="space-y-3">
+          {/* v1.16.4 — a real form so Enter in the username / email
+              fields submits; mirrors the dialog convention. */}
+          <form
+            className="space-y-3"
+            onSubmit={(e) => {
+              e.preventDefault();
+              if (updateUser.isPending) return;
+              updateUser.mutate({
+                id: editingUser.id,
+                data: {
+                  username: editUsername,
+                  email: editEmail || null,
+                },
+              });
+            }}
+          >
             <div className="space-y-1">
               <Label htmlFor="edit-username">{t("auth.username")}</Label>
               <Input
@@ -448,17 +447,10 @@ export function UserManagementSection() {
             </div>
             <div className="flex gap-2">
               <Button
+                type="submit"
                 size="sm"
                 disabled={updateUser.isPending}
-                onClick={() =>
-                  updateUser.mutate({
-                    id: editingUser.id,
-                    data: {
-                      username: editUsername,
-                      email: editEmail || null,
-                    },
-                  })
-                }
+                aria-busy={updateUser.isPending || undefined}
               >
                 {updateUser.isPending && (
                   <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
@@ -466,6 +458,7 @@ export function UserManagementSection() {
                 {t("common.save")}
               </Button>
               <Button
+                type="button"
                 variant="ghost"
                 size="sm"
                 onClick={() => setEditingUser(null)}
@@ -478,7 +471,7 @@ export function UserManagementSection() {
                 </span>
               )}
             </div>
-          </div>
+          </form>
         </div>
       )}
 
diff --git a/src/components/admin/version-tile-section.tsx b/src/components/admin/version-tile-section.tsx
index 32ca869ab..c378ece3b 100644
--- a/src/components/admin/version-tile-section.tsx
+++ b/src/components/admin/version-tile-section.tsx
@@ -21,6 +21,7 @@ import { useQuery } from "@tanstack/react-query";
 import { formatDateTime } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { ApiError, apiGet } from "@/lib/api/api-fetch";
 import { StatusItem, usePublicVersion } from "./_shared";
 
 type CheckUpdatesResult =
@@ -41,11 +42,13 @@ type CheckUpdatesResult =
   | { status: "unknown"; current: string; reason: string };
 
 async function fetchUpdateCheck(): Promise<CheckUpdatesResult> {
-  const res = await fetch("/api/version/check-updates");
-  if (!res.ok) {
-    return { status: "unknown", current: "", reason: `http_${res.status}` };
+  try {
+    return await apiGet<CheckUpdatesResult>("/api/version/check-updates");
+  } catch (err) {
+    const reason =
+      err instanceof ApiError ? `http_${err.status}` : "network_error";
+    return { status: "unknown", current: "", reason };
   }
-  return (await res.json()).data as CheckUpdatesResult;
 }
 
 function shortSha(sha: string | null): string | null {
diff --git a/src/components/app-settings-provider.tsx b/src/components/app-settings-provider.tsx
index e3045a91e..7058359a0 100644
--- a/src/components/app-settings-provider.tsx
+++ b/src/components/app-settings-provider.tsx
@@ -26,6 +26,7 @@ import { createContext, useContext, type ReactNode } from "react";
 import { useQuery } from "@tanstack/react-query";
 import { useAuth } from "@/hooks/use-auth";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 
 export interface AppSettings {
   /** Whether the admin has enabled in-app bug-report / feedback submission. */
@@ -60,10 +61,7 @@ export function AppSettingsProvider({ children }: { children: ReactNode }) {
     queryKey: queryKeys.bugreportStatus(),
     enabled: isAuthenticated,
     queryFn: async () => {
-      const res = await fetch("/api/bugreport/status");
-      if (!res.ok) throw new Error("Failed to load bug-report status");
-      const json = (await res.json()) as { data: BugReportStatusPayload };
-      return json.data;
+      return apiGet<BugReportStatusPayload>("/api/bugreport/status");
     },
     staleTime: 5 * 60 * 1000,
   });
diff --git a/src/components/charts/__tests__/health-chart-empty-state-gate.test.tsx b/src/components/charts/__tests__/health-chart-empty-state-gate.test.tsx
index 847222896..45005b146 100644
--- a/src/components/charts/__tests__/health-chart-empty-state-gate.test.tsx
+++ b/src/components/charts/__tests__/health-chart-empty-state-gate.test.tsx
@@ -1,5 +1,9 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
+// vi.doMock below invalidates the module registry, so the re-imported
+// provider gets a fresh (unprimed) locale cache — pass the DE bundle
+// explicitly instead of relying on the vitest.setup.ts seeding.
+import deMessages from "../../../../messages/de.json";
 
 /**
  * Sparse-data render contract.
@@ -48,7 +52,7 @@ async function renderChart(data: unknown[]): Promise<string> {
   const { HealthChart } = await import("../health-chart");
 
   const html = renderToStaticMarkup(
-    <I18nProvider initialLocale="de">
+    <I18nProvider initialLocale="de" initialMessages={deMessages}>
       <HealthChart types={["PULSE"]} title="Pulse" unit="bpm" />
     </I18nProvider>,
   );
diff --git a/src/components/charts/__tests__/health-chart-no-data-in-range.test.tsx b/src/components/charts/__tests__/health-chart-no-data-in-range.test.tsx
index ab867905c..2226282d6 100644
--- a/src/components/charts/__tests__/health-chart-no-data-in-range.test.tsx
+++ b/src/components/charts/__tests__/health-chart-no-data-in-range.test.tsx
@@ -1,5 +1,9 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
+// vi.doMock below invalidates the module registry, so the re-imported
+// provider gets a fresh (unprimed) locale cache — pass the DE bundle
+// explicitly instead of relying on the vitest.setup.ts seeding.
+import deMessages from "../../../../messages/de.json";
 
 /**
  * v1.4.43 W11-M6 — chart empty-window state.
@@ -49,7 +53,7 @@ describe("<HealthChart> — empty-window state (W11-M6)", () => {
     const { HealthChart } = await import("../health-chart");
 
     const html = renderToStaticMarkup(
-      <I18nProvider initialLocale="de">
+      <I18nProvider initialLocale="de" initialMessages={deMessages}>
         <HealthChart types={["PULSE"]} title="Pulse" unit="bpm" />
       </I18nProvider>,
     );
diff --git a/src/components/charts/__tests__/health-chart-overlay-defaults.test.tsx b/src/components/charts/__tests__/health-chart-overlay-defaults.test.tsx
index f71f548e5..8f379853b 100644
--- a/src/components/charts/__tests__/health-chart-overlay-defaults.test.tsx
+++ b/src/components/charts/__tests__/health-chart-overlay-defaults.test.tsx
@@ -5,7 +5,7 @@ import { fileURLToPath } from "node:url";
 /**
  * v1.4.18 — Default overlay state on chart wrappers.
  *
- * the maintainer rejected the always-on personal-baseline reference line that B1a
+ * The maintainer rejected the always-on personal-baseline reference line that B1a
  * painted on every chart. The default surface for a new chart should be
  * a clean line + axes + tooltip — no baseline, no target-zone shading,
  * no trend line. Overlays are user-opt-in via the per-chart settings
diff --git a/src/components/charts/__tests__/medication-compliance-chart-empty-state-gate.test.tsx b/src/components/charts/__tests__/medication-compliance-chart-empty-state-gate.test.tsx
index e8e0196ff..9a344b43c 100644
--- a/src/components/charts/__tests__/medication-compliance-chart-empty-state-gate.test.tsx
+++ b/src/components/charts/__tests__/medication-compliance-chart-empty-state-gate.test.tsx
@@ -1,5 +1,9 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
+// vi.doMock below invalidates the module registry, so the re-imported
+// provider gets a fresh (unprimed) locale cache — pass the DE bundle
+// explicitly instead of relying on the vitest.setup.ts seeding.
+import deMessages from "../../../../messages/de.json";
 
 /**
  * v1.4.43 W2-CHART-GATE — medication-compliance empty-state copy split.
@@ -49,7 +53,7 @@ describe("<MedicationComplianceChart> — empty-state gate by raw count", () =>
     );
 
     const html = renderToStaticMarkup(
-      <I18nProvider initialLocale="de">
+      <I18nProvider initialLocale="de" initialMessages={deMessages}>
         <MedicationComplianceChart />
       </I18nProvider>,
     );
@@ -80,7 +84,7 @@ describe("<MedicationComplianceChart> — empty-state gate by raw count", () =>
     );
 
     const html = renderToStaticMarkup(
-      <I18nProvider initialLocale="de">
+      <I18nProvider initialLocale="de" initialMessages={deMessages}>
         <MedicationComplianceChart />
       </I18nProvider>,
     );
diff --git a/src/components/charts/__tests__/mood-chart-empty-state-gate.test.tsx b/src/components/charts/__tests__/mood-chart-empty-state-gate.test.tsx
index ab360d232..1733651b2 100644
--- a/src/components/charts/__tests__/mood-chart-empty-state-gate.test.tsx
+++ b/src/components/charts/__tests__/mood-chart-empty-state-gate.test.tsx
@@ -1,5 +1,9 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
+// vi.doMock below invalidates the module registry, so the re-imported
+// provider gets a fresh (unprimed) locale cache — pass the DE bundle
+// explicitly instead of relying on the vitest.setup.ts seeding.
+import deMessages from "../../../../messages/de.json";
 
 /**
  * v1.4.43 W2-CHART-GATE — mood-chart empty-state copy split.
@@ -49,7 +53,7 @@ describe("<MoodChart> — empty-state gate by raw count", () => {
     const { MoodChart } = await import("../mood-chart");
 
     const html = renderToStaticMarkup(
-      <I18nProvider initialLocale="de">
+      <I18nProvider initialLocale="de" initialMessages={deMessages}>
         <MoodChart />
       </I18nProvider>,
     );
@@ -81,7 +85,7 @@ describe("<MoodChart> — empty-state gate by raw count", () => {
     const { MoodChart } = await import("../mood-chart");
 
     const html = renderToStaticMarkup(
-      <I18nProvider initialLocale="de">
+      <I18nProvider initialLocale="de" initialMessages={deMessages}>
         <MoodChart />
       </I18nProvider>,
     );
diff --git a/src/components/charts/__tests__/mood-chart-polish.test.tsx b/src/components/charts/__tests__/mood-chart-polish.test.tsx
index 32a1642a8..41cad2fc3 100644
--- a/src/components/charts/__tests__/mood-chart-polish.test.tsx
+++ b/src/components/charts/__tests__/mood-chart-polish.test.tsx
@@ -6,7 +6,7 @@ import { fileURLToPath } from "node:url";
 /**
  * v1.4.18 — MoodChart clean-line revert (gradient + emoji rolled back).
  *
- * the maintainer rejected B1a's coloured area fill below the chart line and the
+ * The maintainer rejected B1a's coloured area fill below the chart line and the
  * smiley/emoji glyphs at every data point. The line stroke + Dracula
  * tokens stay; the chart now paints a clean monotone line with simple
  * Recharts dots.
@@ -67,7 +67,7 @@ describe("<MoodChart> v1.4.18 clean-line revert", () => {
   });
 
   it("does NOT render emoji glyphs at data points (source check)", async () => {
-    // the maintainer explicitly rejected smileys, especially in the mood chart.
+    // The maintainer explicitly rejected smileys, especially in the mood chart.
     // Recharts does not paint <Line> dots during SSR (the dot callback
     // only fires after first client render), so the emoji wouldn't
     // surface in renderToStaticMarkup output anyway. Inspecting the
diff --git a/src/components/charts/__tests__/trend-card-baseline-alignment.test.tsx b/src/components/charts/__tests__/trend-card-baseline-alignment.test.tsx
index 20831365a..bed73b3f1 100644
--- a/src/components/charts/__tests__/trend-card-baseline-alignment.test.tsx
+++ b/src/components/charts/__tests__/trend-card-baseline-alignment.test.tsx
@@ -8,7 +8,7 @@ import { I18nProvider } from "@/lib/i18n/context";
 /**
  * v1.4.25 W20a — regression coverage for the dashboard top-tile polish.
  *
- * Marc-direktive 2026-05-14 named three issues with the 5-tile top row:
+ * Maintainer directive 2026-05-14 named three issues with the 5-tile top row:
  *
  *   1. Headings wrapped to two lines at narrow viewports (e.g. "Blood
  *      Pressure" on Pixel 5 / 393 px / 2-col grid). Locked the heading
diff --git a/src/components/charts/chart-overlay-controls.tsx b/src/components/charts/chart-overlay-controls.tsx
index b05542878..f7e188815 100644
--- a/src/components/charts/chart-overlay-controls.tsx
+++ b/src/components/charts/chart-overlay-controls.tsx
@@ -23,7 +23,7 @@ import {
 /**
  * v1.4.18 — per-chart overlay-controls popover.
  *
- * the maintainer rolled back B1a's always-on chart overlays (gradient fills,
+ * The maintainer rolled back B1a's always-on chart overlays (gradient fills,
  * personal-baseline reference line, target-zone shading) and asked for
  * a per-chart switch surface instead. Each dashboard chart card mounts
  * one of these in its top-right corner (a settings-cog dropdown) so the
diff --git a/src/components/charts/health-chart.tsx b/src/components/charts/health-chart.tsx
index 19813c9a9..ea1d4417e 100644
--- a/src/components/charts/health-chart.tsx
+++ b/src/components/charts/health-chart.tsx
@@ -3,6 +3,7 @@
 import { useQuery } from "@tanstack/react-query";
 import { useAuth } from "@/hooks/use-auth";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import {
   ResponsiveContainer,
   ComposedChart,
@@ -707,13 +708,16 @@ export function HealthChart({
           "days",
           String(Math.max(1, Math.min(3650, Math.ceil(fetchWindow.windowDays)))),
         );
-        const res = await fetch(`/api/measurements/series?${sleepParams}`);
-        if (!res.ok) return;
-        const json = await res.json();
-        const points = (json.data?.points ?? []) as Array<{
-          at: string;
-          value: number;
-        }>;
+        let points: Array<{ at: string; value: number }>;
+        try {
+          const data = await apiGet<{
+            points?: Array<{ at: string; value: number }>;
+          }>(`/api/measurements/series?${sleepParams}`);
+          points = data?.points ?? [];
+        } catch {
+          // Sleep overlay is additive — skip it on failure, as before.
+          return;
+        }
         for (const point of points) {
           const value = point.value * valueScale;
           if (value == null || !Number.isFinite(value)) continue;
@@ -769,11 +773,16 @@ export function HealthChart({
           typeParams.set("source", "rollup");
         }
 
-        const res = await fetch(`/api/measurements?${typeParams}`);
-        if (!res.ok) return;
-
-        const json = await res.json();
-        const page = (json.data?.measurements ?? []) as MeasurementApiRow[];
+        let page: MeasurementApiRow[];
+        try {
+          const data = await apiGet<{ measurements?: MeasurementApiRow[] }>(
+            `/api/measurements?${typeParams}`,
+          );
+          page = data?.measurements ?? [];
+        } catch {
+          // Per-type fetch failure degrades that series only, as before.
+          return;
+        }
 
         for (const measurement of page) {
           // v1.7.0 — fold the display-time scale into the raw value at
diff --git a/src/components/charts/medication-compliance-chart.tsx b/src/components/charts/medication-compliance-chart.tsx
index 64440773d..3f7b81b92 100644
--- a/src/components/charts/medication-compliance-chart.tsx
+++ b/src/components/charts/medication-compliance-chart.tsx
@@ -61,6 +61,7 @@ import { prefersReducedMotion } from "@/lib/charts/reduced-motion";
 import { useChartOverlayPrefs } from "@/hooks/use-chart-overlay-prefs";
 import { useViewportWidth } from "@/hooks/use-viewport-width";
 import { chooseTickInterval } from "@/lib/charts/x-axis-density";
+import { apiGet } from "@/lib/api/api-fetch";
 
 interface DailyCompliancePoint {
   /** Berlin calendar day, "YYYY-MM-DD". */
@@ -244,12 +245,7 @@ export function MedicationComplianceChart({
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.dashboardMedicationCompliance(days),
     queryFn: async (): Promise<DailyCompliancePoint[]> => {
-      const res = await fetch(
-        `/api/medications/intake?scope=compliance&days=${days}`,
-      );
-      if (!res.ok) throw new Error("failed to fetch medication compliance");
-      const json = await res.json();
-      return json.data as DailyCompliancePoint[];
+      return apiGet<DailyCompliancePoint[]>(`/api/medications/intake?scope=compliance&days=${days}`);
     },
     enabled: isAuthenticated,
   });
diff --git a/src/components/charts/mood-chart.tsx b/src/components/charts/mood-chart.tsx
index a0ce05733..da8fd1cf5 100644
--- a/src/components/charts/mood-chart.tsx
+++ b/src/components/charts/mood-chart.tsx
@@ -40,6 +40,7 @@ import { useViewportWidth } from "@/hooks/use-viewport-width";
 import { computeTickPositions } from "@/lib/charts/x-axis-density";
 import { CHART_HEIGHT_PX } from "@/lib/charts/constants";
 import { moodLabelKeyForScore } from "@/lib/mood/labels";
+import { apiGet } from "@/lib/api/api-fetch";
 
 // --- Types ---
 
@@ -348,10 +349,7 @@ export function MoodChart({
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.moodAnalytics(),
     queryFn: async (): Promise<MoodAnalyticsData> => {
-      const res = await fetch("/api/mood/analytics");
-      if (!res.ok) throw new Error("Failed to fetch mood analytics");
-      const json = await res.json();
-      return json.data as MoodAnalyticsData;
+      return apiGet<MoodAnalyticsData>("/api/mood/analytics");
     },
     enabled: isAuthenticated,
     staleTime: 60_000,
diff --git a/src/components/charts/trend-card.tsx b/src/components/charts/trend-card.tsx
index e69183791..c41eb292f 100644
--- a/src/components/charts/trend-card.tsx
+++ b/src/components/charts/trend-card.tsx
@@ -208,7 +208,7 @@ export function TrendCard({
           to land at different heights when one tile had a one-line heading
           and another had a two-line wrap). The arrow slot is always
           present — when there is no signal yet, a muted "—" placeholder
-          renders so the value row keeps a deterministic width. Marc's
+          renders so the value row keeps a deterministic width. The maintainer's
           ask: "rechts neben der Zahl … der Pfeil [ist], wie gerade der
           Trend ist". */}
       <div
diff --git a/src/components/comparison/compare-toggle.tsx b/src/components/comparison/compare-toggle.tsx
index cb9e52f60..474f4105e 100644
--- a/src/components/comparison/compare-toggle.tsx
+++ b/src/components/comparison/compare-toggle.tsx
@@ -10,6 +10,7 @@ import {
   type ComparisonBaseline,
   type DashboardLayout,
 } from "@/lib/dashboard-layout";
+import { apiGet, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.16 phase D reconcile (CRITICAL C3) — on-surface comparison
@@ -29,10 +30,7 @@ export function CompareToggle({ className }: { className?: string }) {
   const { data: layoutData } = useQuery({
     queryKey: queryKeys.dashboardWidgets(),
     queryFn: async () => {
-      const res = await fetch("/api/dashboard/widgets");
-      if (!res.ok) throw new Error("failed");
-      const json = await res.json();
-      return json.data as DashboardLayout;
+      return apiGet<DashboardLayout>("/api/dashboard/widgets");
     },
   });
 
@@ -43,13 +41,7 @@ export function CompareToggle({ className }: { className?: string }) {
     mutationFn: async (next: ComparisonBaseline) => {
       if (!layout) throw new Error("layout-not-loaded");
       const body: DashboardLayout = { ...layout, comparisonBaseline: next };
-      const res = await fetch("/api/dashboard/widgets", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      if (!res.ok) throw new Error("save-failed");
-      return (await res.json()).data as DashboardLayout;
+      return apiPut<DashboardLayout>("/api/dashboard/widgets", body);
     },
     onMutate: async (next) => {
       await queryClient.cancelQueries({
diff --git a/src/components/cycle/log-day-sheet.tsx b/src/components/cycle/log-day-sheet.tsx
index b8cf61fef..c80170167 100644
--- a/src/components/cycle/log-day-sheet.tsx
+++ b/src/components/cycle/log-day-sheet.tsx
@@ -369,33 +369,56 @@ export function LogDaySheet({
       note,
       symptoms,
     };
-    if (rowId) {
-      // Editing an existing row → PATCH with explicit nulls so a deselected
-      // chip actually CLEARS (the POST merge can only add/keep — QA W-2).
-      await patchDay.mutateAsync({ id: rowId, patch: buildDayLogPatch(state) });
+    // v1.16.4 — catch so a rejected save doesn't escape as an unhandled
+    // rejection; the inline `logDay.isError || patchDay.isError` strip in the
+    // footer carries the visible failure signal and the sheet stays open.
+    try {
+      if (rowId) {
+        // Editing an existing row → PATCH with explicit nulls so a deselected
+        // chip actually CLEARS (the POST merge can only add/keep — QA W-2).
+        await patchDay.mutateAsync({
+          id: rowId,
+          patch: buildDayLogPatch(state),
+        });
+      } else {
+        await logDay.mutateAsync(buildDayLogInput(state, date));
+      }
       onOpenChange(false);
-      return;
+    } catch {
+      /* surfaced via the inline isError strip */
     }
-    await logDay.mutateAsync(buildDayLogInput(state, date));
-    onOpenChange(false);
   }
 
   // Period boundaries operate on the SELECTED date, so a forgotten day-1 can be
   // corrected from the calendar retroactively (QA M3) — not today-only.
+  // v1.16.4 — the rejection is surfaced as a toast by the hook's onError;
+  // catching here keeps the sheet open without an unhandled rejection.
   async function handleStartPeriod() {
-    await startPeriod.mutateAsync(date);
-    onOpenChange(false);
+    try {
+      await startPeriod.mutateAsync(date);
+      onOpenChange(false);
+    } catch {
+      /* toast shown by useStartPeriod onError */
+    }
   }
 
   async function handleEndPeriod() {
-    await endPeriod.mutateAsync(date);
-    onOpenChange(false);
+    try {
+      await endPeriod.mutateAsync(date);
+      onOpenChange(false);
+    } catch {
+      /* toast shown by useEndPeriod onError */
+    }
   }
 
   async function handleDelete() {
     if (!rowId) return;
-    await deleteDay.mutateAsync(rowId);
-    onOpenChange(false);
+    try {
+      await deleteDay.mutateAsync(rowId);
+      onOpenChange(false);
+    } catch {
+      /* toast shown by useDeleteDayLog onError */
+    }
   }
 
   const busy =
@@ -757,7 +780,11 @@ function SymptomChip({
   async function handleRemove() {
     if (!custom) return;
     onClear?.(custom.key);
-    await deleteCustom.mutateAsync(custom.key);
+    try {
+      await deleteCustom.mutateAsync(custom.key);
+    } catch {
+      /* toast shown by useDeleteCustomSymptom onError */
+    }
   }
 
   return (
diff --git a/src/components/cycle/use-cycle.ts b/src/components/cycle/use-cycle.ts
index 4a3441386..dc5d94a48 100644
--- a/src/components/cycle/use-cycle.ts
+++ b/src/components/cycle/use-cycle.ts
@@ -10,6 +10,16 @@
  * log.
  */
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { toast } from "sonner";
+
+import {
+  ApiError,
+  apiDelete,
+  apiGet,
+  apiPatch,
+  apiPost,
+} from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
 
 import {
   cycleDependentKeys,
@@ -52,12 +62,6 @@ export interface CycleInsightsResponse {
   symptomPatterns: SymptomPhaseRow[];
 }
 
-async function unwrap<T>(res: Response): Promise<T> {
-  if (!res.ok) throw new Error(`Request failed: ${res.status}`);
-  const json = await res.json();
-  return json.data as T;
-}
-
 /**
  * The local-timezone `YYYY-MM-DD` for a Date (default: now). Cycle day-keys
  * are tz-anchored on the server; the client must derive the key from the
@@ -81,9 +85,7 @@ export function useCycleDayLog(date: string | null) {
     queryKey: queryKeys.cycleDayLog(date ?? ""),
     enabled: date !== null,
     queryFn: () =>
-      fetch(`/api/cycle/day-logs?date=${date}`).then((r) =>
-        unwrap<CycleDayLogDTO | null>(r),
-      ),
+      apiGet<CycleDayLogDTO | null>(`/api/cycle/day-logs?date=${date}`),
     staleTime: 30_000,
   });
 }
@@ -92,9 +94,7 @@ export function useCycleCalendar(from: string, to: string) {
   return useQuery({
     queryKey: queryKeys.cycleCalendar(from, to),
     queryFn: () =>
-      fetch(`/api/cycle/calendar?from=${from}&to=${to}`).then((r) =>
-        unwrap<CalendarResponse>(r),
-      ),
+      apiGet<CalendarResponse>(`/api/cycle/calendar?from=${from}&to=${to}`),
     staleTime: 60_000,
   });
 }
@@ -103,9 +103,7 @@ export function useCycleHistory(limit = 24) {
   return useQuery({
     queryKey: queryKeys.cycleHistory(limit),
     queryFn: () =>
-      fetch(`/api/cycle/cycles?limit=${limit}`).then((r) =>
-        unwrap<CycleHistoryResponse>(r),
-      ),
+      apiGet<CycleHistoryResponse>(`/api/cycle/cycles?limit=${limit}`),
     staleTime: 60_000,
   });
 }
@@ -126,9 +124,7 @@ export function useCustomSymptoms() {
   return useQuery({
     queryKey: queryKeys.cycleCustomSymptoms(),
     queryFn: () =>
-      fetch("/api/cycle/symptoms/custom").then((r) =>
-        unwrap<{ symptoms: CustomSymptomDTO[] }>(r),
-      ),
+      apiGet<{ symptoms: CustomSymptomDTO[] }>("/api/cycle/symptoms/custom"),
     staleTime: 5 * 60_000,
   });
 }
@@ -152,22 +148,22 @@ export function useCreateCustomSymptom() {
   const qc = useQueryClient();
   return useMutation({
     mutationFn: async (input: { label: string; icon?: string | null }) => {
-      const res = await fetch("/api/cycle/symptoms/custom", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(input),
-      });
-      if (!res.ok) {
+      try {
+        return await apiPost<CustomSymptomDTO>(
+          "/api/cycle/symptoms/custom",
+          input,
+        );
+      } catch (e) {
         // Preserve the envelope errorCode so the UI can tell the cap hit
         // (cycle.symptom.custom.limit) apart from a transient/validation error.
-        const errorCode = await res
-          .json()
-          .then((j) => (j?.meta?.errorCode as string | undefined) ?? null)
-          .catch(() => null);
-        throw new CustomSymptomError(errorCode, res.status);
+        if (e instanceof ApiError) {
+          throw new CustomSymptomError(
+            (e.meta?.errorCode as string | undefined) ?? null,
+            e.status,
+          );
+        }
+        throw e;
       }
-      const json = await res.json();
-      return json.data as CustomSymptomDTO;
     },
     onSuccess: () =>
       qc.invalidateQueries({ queryKey: queryKeys.cycleCustomSymptoms() }),
@@ -177,15 +173,17 @@ export function useCreateCustomSymptom() {
 /** Soft-hide a custom symptom by its key (history-preserving). */
 export function useDeleteCustomSymptom() {
   const qc = useQueryClient();
+  const { t } = useTranslations();
   return useMutation({
     mutationFn: async (key: string) => {
-      const res = await fetch(
+      return apiDelete<{ key: string; purged: boolean }>(
         `/api/cycle/symptoms/custom/${encodeURIComponent(key)}`,
-        { method: "DELETE" },
       );
-      return unwrap<{ key: string; purged: boolean }>(res);
     },
     onSuccess: () => invalidateKeys(qc, cycleDependentKeys),
+    // v1.16.4 — a failed delete used to fail silently (the sheet clears the
+    // chip optimistically), so surface the rejection.
+    onError: () => toast.error(t("cycle.deleteError")),
   });
 }
 
@@ -193,7 +191,7 @@ export function useCycleProfile() {
   return useQuery({
     queryKey: queryKeys.cycleProfile(),
     queryFn: () =>
-      fetch("/api/cycle/profile").then((r) => unwrap<CycleProfileDTO>(r)),
+      apiGet<CycleProfileDTO>("/api/cycle/profile"),
     staleTime: 5 * 60_000,
   });
 }
@@ -207,9 +205,7 @@ export function useCycleInsights() {
   return useQuery({
     queryKey: queryKeys.cycleInsights(),
     queryFn: () =>
-      fetch("/api/cycle/insights").then((r) =>
-        unwrap<CycleInsightsResponse>(r),
-      ),
+      apiGet<CycleInsightsResponse>("/api/cycle/insights"),
     staleTime: 5 * 60_000,
   });
 }
@@ -223,15 +219,9 @@ export function useLogDay() {
   const qc = useQueryClient();
   return useMutation({
     mutationFn: async (input: CycleDayLogInput) => {
-      const res = await fetch("/api/cycle/day-logs", {
-        method: "POST",
-        headers: {
-          "Content-Type": "application/json",
-          "Idempotency-Key": idempotencyKey(),
-        },
-        body: JSON.stringify(input),
+      return apiPost<unknown>("/api/cycle/day-logs", input, {
+        headers: { "Idempotency-Key": idempotencyKey() },
       });
-      return unwrap<unknown>(res);
     },
     onSuccess: () => invalidateKeys(qc, cycleDependentKeys),
   });
@@ -269,12 +259,7 @@ export function usePatchDayLog() {
       id: string;
       patch: CycleDayLogPatch;
     }) => {
-      const res = await fetch(`/api/cycle/day-logs/${id}`, {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(patch),
-      });
-      return unwrap<CycleDayLogDTO>(res);
+      return apiPatch<CycleDayLogDTO>(`/api/cycle/day-logs/${id}`, patch);
     },
     onSuccess: () => invalidateKeys(qc, cycleDependentKeys),
   });
@@ -282,56 +267,49 @@ export function usePatchDayLog() {
 
 export function useStartPeriod() {
   const qc = useQueryClient();
+  const { t } = useTranslations();
   return useMutation({
     mutationFn: async (date: string) => {
-      const res = await fetch("/api/cycle/period", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          action: "start",
-          date,
-          loggedAt: new Date().toISOString(),
-        }),
+      return apiPost<unknown>("/api/cycle/period", {
+        action: "start",
+        date,
+        loggedAt: new Date().toISOString(),
       });
-      return unwrap<unknown>(res);
     },
     onSuccess: () => invalidateKeys(qc, cycleDependentKeys),
+    // v1.16.4 — period boundaries had no failure signal at all (the sheet
+    // simply stayed open); a toast names the rejection.
+    onError: () => toast.error(t("cycle.saveError")),
   });
 }
 
 /** The one-tap "end period" boundary (`action:"end"`). */
 export function useEndPeriod() {
   const qc = useQueryClient();
+  const { t } = useTranslations();
   return useMutation({
     mutationFn: async (date: string) => {
-      const res = await fetch("/api/cycle/period", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          action: "end",
-          date,
-          loggedAt: new Date().toISOString(),
-        }),
+      return apiPost<unknown>("/api/cycle/period", {
+        action: "end",
+        date,
+        loggedAt: new Date().toISOString(),
       });
-      return unwrap<unknown>(res);
     },
     onSuccess: () => invalidateKeys(qc, cycleDependentKeys),
+    onError: () => toast.error(t("cycle.saveError")),
   });
 }
 
 /** Soft-delete a logged day by its row id (the GET supplies the id). */
 export function useDeleteDayLog() {
   const qc = useQueryClient();
+  const { t } = useTranslations();
   return useMutation({
     mutationFn: async (id: string) => {
-      const res = await fetch(`/api/cycle/day-logs/${id}`, {
-        method: "DELETE",
-      });
-      if (!res.ok && res.status !== 204) {
-        throw new Error(`Request failed: ${res.status}`);
-      }
+      await apiDelete(`/api/cycle/day-logs/${id}`);
     },
     onSuccess: () => invalidateKeys(qc, cycleDependentKeys),
+    onError: () => toast.error(t("cycle.deleteError")),
   });
 }
 
@@ -351,12 +329,7 @@ export function useUpdateCyclePrefs() {
   const qc = useQueryClient();
   return useMutation({
     mutationFn: async (patch: CyclePrefsPatch) => {
-      const res = await fetch("/api/auth/me/cycle-prefs", {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(patch),
-      });
-      return unwrap<CycleProfileDTO>(res);
+      return apiPatch<CycleProfileDTO>("/api/auth/me/cycle-prefs", patch);
     },
     onSuccess: () => {
       void invalidateKeys(qc, cycleDependentKeys);
diff --git a/src/components/dashboard/__tests__/medication-intake-quick-add.test.tsx b/src/components/dashboard/__tests__/medication-intake-quick-add.test.tsx
index 79f0ccea6..df9042c79 100644
--- a/src/components/dashboard/__tests__/medication-intake-quick-add.test.tsx
+++ b/src/components/dashboard/__tests__/medication-intake-quick-add.test.tsx
@@ -6,7 +6,7 @@
  * assertions below cover:
  *
  *   1. The pure `pickDefaultMedicationId` helper — the cool/easy
- *      default-selection logic Marc asked for ("auto-select when one is
+ *      default-selection logic the maintainer asked for ("auto-select when one is
  *      due"). Tested across the four ranked branches: empty,
  *      single-active, due-now, alphabetical fallback.
  *   2. The empty-state SSR markup — when the user has no active
@@ -183,7 +183,7 @@ describe("<MedicationIntakeQuickAdd> — SSR contract", () => {
     const de = renderSSR(<MedicationIntakeQuickAdd />, "de");
     expect(en).not.toContain("dashboard.medicationIntakeQuickAdd");
     expect(de).not.toContain("dashboard.medicationIntakeQuickAdd");
-    // German locale ships Marc-Voice DE copy with umlauts (UTF-8
+    // German locale ships project-voice DE copy with umlauts (UTF-8
     // end-to-end, never their HTML entity form).
     expect(de).toContain("Medikamente angelegt");
   });
diff --git a/src/components/dashboard/medication-intake-quick-add.tsx b/src/components/dashboard/medication-intake-quick-add.tsx
index b9dab9081..353156978 100644
--- a/src/components/dashboard/medication-intake-quick-add.tsx
+++ b/src/components/dashboard/medication-intake-quick-add.tsx
@@ -28,11 +28,12 @@ import {
   toBerlinDate,
   type ScheduleWindowInput,
 } from "@/lib/medications/window-status";
+import { ApiError, apiGet, apiPost } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.37 W7b — dashboard "Hinzufügen" → "Medikamenteneinnahme" quick-add.
  *
- * Marc's brief: the dashboard's top-right "Hinzufügen" menu logs
+ * The maintainer's brief: the dashboard's top-right "Hinzufügen" menu logs
  * measurements and mood entries; add a medication-intake action so a
  * dose can be logged in a few taps without leaving the dashboard.
  *
@@ -157,10 +158,7 @@ export function MedicationIntakeQuickAdd({
   const { data: medicationsRaw, isLoading: medicationsLoading } = useQuery({
     queryKey: queryKeys.medications(),
     queryFn: async () => {
-      const res = await fetch("/api/medications");
-      if (!res.ok) throw new Error("Failed to load medications");
-      const json = await res.json();
-      return json.data as MedicationOption[];
+      return apiGet<MedicationOption[]>("/api/medications");
     },
     // v1.4.38 — share the parent dashboard's medications cache.
     // `queryKeys.medications()` resolves to `["medications"]` — the
@@ -241,27 +239,12 @@ export function MedicationIntakeQuickAdd({
       const doseDeviates =
         trimmedDose.length > 0 &&
         trimmedDose !== (selectedMedication?.dose ?? "").trim();
-      const res = await fetch(`/api/medications/${medicationId}/intake`, {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          takenAt: timestamp,
-          skipped: false,
-          ...(doseDeviates && { doseTaken: trimmedDose }),
-        }),
+      await apiPost(`/api/medications/${medicationId}/intake`, {
+        takenAt: timestamp,
+        skipped: false,
+        ...(doseDeviates && { doseTaken: trimmedDose }),
       });
 
-      const json = await res.json();
-      if (!res.ok) {
-        setError(
-          typeof json?.error === "string"
-            ? json.error
-            : t("dashboard.medicationIntakeQuickAdd.saveError"),
-        );
-        setLoading(false);
-        return;
-      }
-
       await invalidateKeys(queryClient, medicationDependentKeys);
       // Fan-out to every inline compliance chart key (one per medication)
       // so the detail-page tile refreshes when the user re-enters it.
@@ -271,8 +254,12 @@ export function MedicationIntakeQuickAdd({
 
       toast.success(t("common.saved"));
       onSuccess?.();
-    } catch {
-      setError(t("dashboard.medicationIntakeQuickAdd.saveError"));
+    } catch (err) {
+      setError(
+        err instanceof ApiError && err.message
+          ? err.message
+          : t("dashboard.medicationIntakeQuickAdd.saveError"),
+      );
     } finally {
       setLoading(false);
     }
diff --git a/src/components/doctor-report/doctor-report-dialog.tsx b/src/components/doctor-report/doctor-report-dialog.tsx
index 12e1b927c..ad53fc728 100644
--- a/src/components/doctor-report/doctor-report-dialog.tsx
+++ b/src/components/doctor-report/doctor-report-dialog.tsx
@@ -8,13 +8,13 @@
  *   2. Practice / clinic name (optional, persisted between exports).
  *   3. Which data sections appear in the PDF (per-user persisted toggles).
  *
- * Hide-when-empty (Marc 2026-05-14): a section's toggle is only shown
+ * Hide-when-empty (the maintainer 2026-05-14): a section's toggle is only shown
  * when the selected date range actually has data for it — checking a box
  * for an empty section would produce a silently-empty PDF page. The
  * availability probe runs on every range change via
  * `/api/doctor-report/availability`.
  *
- * Privacy default: mood is OFF by default per Marc — mental-health data
+ * Privacy default: mood is OFF by default per the maintainer — mental-health data
  * is opt-in even within a single user's own surface. The API layer
  * filters mood out of the report payload server-side when the toggle is
  * off, so the data never leaves the DB row.
@@ -52,6 +52,7 @@ import {
   type DoctorReportPrefs,
 } from "@/lib/validations/doctor-report-prefs";
 import { useTranslations } from "@/lib/i18n/context";
+import { apiGet, apiPost, apiPut } from "@/lib/api/api-fetch";
 
 const ONE_DAY_MS = 86_400_000;
 const MAX_RANGE_DAYS = 730;
@@ -201,11 +202,12 @@ export function DoctorReportDialog({
   useEffect(() => {
     if (!open || prefsLoaded) return;
     let cancelled = false;
-    fetch("/api/auth/me/doctor-report-prefs", { credentials: "include" })
-      .then((res) => (res.ok ? res.json() : null))
-      .then((json) => {
+    apiGet<Partial<DoctorReportPrefs> | null | undefined>(
+      "/api/auth/me/doctor-report-prefs",
+      { credentials: "include" },
+    )
+      .then((incoming) => {
         if (cancelled) return;
-        const incoming = json?.data;
         if (incoming && typeof incoming === "object") {
           setPrefs({ ...DEFAULT_DOCTOR_REPORT_PREFS, ...incoming });
         }
@@ -236,18 +238,16 @@ export function DoctorReportDialog({
       .then(() => {
         if (cancelled) return null;
         setAvailabilityLoading(true);
-        return fetch("/api/doctor-report/availability", {
-          method: "POST",
-          headers: { "Content-Type": "application/json" },
-          credentials: "include",
-          body: JSON.stringify({ startDate: startIso, endDate: endIso }),
-        });
+        return apiPost<SectionAvailability>(
+          "/api/doctor-report/availability",
+          { startDate: startIso, endDate: endIso },
+          { credentials: "include" },
+        );
       })
-      .then(async (res) => {
-        if (cancelled || !res || !res.ok) return;
-        const json = (await res.json()) as { data: SectionAvailability };
+      .then((data) => {
+        if (cancelled || !data) return;
         if (requestId !== availabilityRequestId.current) return;
-        setAvailability(json.data);
+        setAvailability(data);
       })
       .catch(() => {
         // Best-effort — keep the previous availability snapshot.
@@ -320,11 +320,8 @@ export function DoctorReportDialog({
     // way, so the user gets the PDF they asked for even if persistence
     // failed (they'll just see the defaults next time).
     try {
-      await fetch("/api/auth/me/doctor-report-prefs", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
+      await apiPut("/api/auth/me/doctor-report-prefs", next, {
         credentials: "include",
-        body: JSON.stringify(next),
       });
     } catch {
       // ignore
diff --git a/src/components/insights/__tests__/health-score-card.test.tsx b/src/components/insights/__tests__/health-score-card.test.tsx
index c6f3b7158..ade8459ed 100644
--- a/src/components/insights/__tests__/health-score-card.test.tsx
+++ b/src/components/insights/__tests__/health-score-card.test.tsx
@@ -334,7 +334,7 @@ describe("<HealthScoreCard>", () => {
   // (the provenance accordion) instead of clumping under the
   // disclaimer. Pin both the grid switch and the `1fr` slack row so
   // a future refactor can't silently revert to flex and re-introduce
-  // the "Karte hört bei der Trennlinie auf" Marc-reported bug.
+  // the "Karte hört bei der Trennlinie auf" maintainer-reported bug.
   it("uses a 7-row grid on the inner column so slack distributes on the accordion row", () => {
     const html = ssr(
       <HealthScoreCard
diff --git a/src/components/insights/coach-panel/__tests__/coach-input.test.tsx b/src/components/insights/coach-panel/__tests__/coach-input.test.tsx
index fc49697c9..5fb65b000 100644
--- a/src/components/insights/coach-panel/__tests__/coach-input.test.tsx
+++ b/src/components/insights/coach-panel/__tests__/coach-input.test.tsx
@@ -50,7 +50,7 @@ describe("<CoachInput>", () => {
 
   it("no longer renders a mic button (W5 removed the placeholder)", () => {
     // v1.4.25 W5 — the mic icon used to be rendered + disabled with a
-    // "voice arrives with iOS" tooltip. Marc flagged it as a click-
+    // "voice arrives with iOS" tooltip. The maintainer flagged it as a click-
     // trap: nothing happened on tap. The composer now drops the icon
     // entirely; voice input remains a v1.5 iOS feature.
     const html = render(
diff --git a/src/components/insights/coach-panel/__tests__/message-thread.test.tsx b/src/components/insights/coach-panel/__tests__/message-thread.test.tsx
index d3bcfefea..fb6748885 100644
--- a/src/components/insights/coach-panel/__tests__/message-thread.test.tsx
+++ b/src/components/insights/coach-panel/__tests__/message-thread.test.tsx
@@ -204,7 +204,7 @@ describe("<MessageThread>", () => {
       />,
     );
     // v1.4.33 IW7 — copy rewritten from "AI provider" to "Insights
-    // provider" per the Marc-Voice rule (no "KI"/"AI" prefix in
+    // provider" per the project-voice rule (no "KI"/"AI" prefix in
     // user-facing strings).
     expect(html).toContain("could not reach an Insights provider");
   });
@@ -423,7 +423,7 @@ describe("<MessageThread>", () => {
     useAuthMock.mockReturnValueOnce({
       user: {
         id: "u-1",
-        username: "marc",
+        username: "testuser",
         role: "USER",
         avatarUrl: "/api/user/avatar/u-1?v=1700000000000",
       },
diff --git a/src/components/insights/coach-panel/message-thread.tsx b/src/components/insights/coach-panel/message-thread.tsx
index 8c063518d..d70fbdb5b 100644
--- a/src/components/insights/coach-panel/message-thread.tsx
+++ b/src/components/insights/coach-panel/message-thread.tsx
@@ -2,6 +2,7 @@
 
 import { useEffect, useId, useMemo, useRef, useState } from "react";
 import { useMutation } from "@tanstack/react-query";
+import { toast } from "sonner";
 import {
   Bot,
   ChevronRight,
@@ -14,6 +15,7 @@ import {
 import { cn } from "@/lib/utils";
 import { scrollBehaviorForUser } from "@/lib/motion";
 import { useTranslations } from "@/lib/i18n/context";
+import { ApiError, apiPost } from "@/lib/api/api-fetch";
 import { stripChartTokens } from "@/lib/insights/chart-tokens";
 import { useAuth } from "@/hooks/use-auth";
 
@@ -118,7 +120,7 @@ export function MessageThread({
   // v1.4.27 F14 — the evidence disclosure used to honour an opt-in
   // `coachPrefs.showEvidenceByDefault` flag that surfaced the raw
   // measurement values unconditionally. The flag created an UX trap
-  // (Marc 2026-05-15: "literal metric values exposed under every
+  // (the maintainer 2026-05-15: "literal metric values exposed under every
   // bubble") so the disclosure is now collapsed by default for every
   // reply. The user expands by click; the pref is retired in the
   // settings sheet so nothing flips it back on.
@@ -617,22 +619,25 @@ function CoachMessageFeedback({ messageId }: CoachMessageFeedbackProps) {
 
   const submit = useMutation({
     mutationFn: async (rating: "helpful" | "unhelpful") => {
-      const res = await fetch(
-        `/api/insights/chat/messages/${messageId}/feedback`,
-        {
-          method: "POST",
-          headers: { "Content-Type": "application/json" },
-          body: JSON.stringify({ rating }),
-        },
-      );
-      // Treat 409 (already_rated) as a successful no-op so the user
-      // never sees an error toast for double-clicking the same chip.
-      if (!res.ok && res.status !== 409) {
-        throw new Error("coach-feedback.failed");
+      try {
+        await apiPost(`/api/insights/chat/messages/${messageId}/feedback`, {
+          rating,
+        });
+      } catch (err) {
+        // Treat 409 (already_rated) as a successful no-op so the user
+        // never sees an error toast for double-clicking the same chip.
+        if (!(err instanceof ApiError && err.status === 409)) {
+          throw err;
+        }
       }
       return rating;
     },
     onSuccess: (rating) => setSubmittedRating(rating),
+    // v1.16.4 — a failed rating used to fail silently; the chips stayed
+    // tappable with no signal that nothing was recorded.
+    onError: () => {
+      toast.error(t("insights.coach.feedbackError"));
+    },
   });
 
   if (submittedRating) {
diff --git a/src/components/insights/coach-panel/self-context-adopt-offer.tsx b/src/components/insights/coach-panel/self-context-adopt-offer.tsx
index 525208d60..e17412c55 100644
--- a/src/components/insights/coach-panel/self-context-adopt-offer.tsx
+++ b/src/components/insights/coach-panel/self-context-adopt-offer.tsx
@@ -19,6 +19,7 @@ import { BookmarkPlus, Check, Loader2, X } from "lucide-react";
 
 import { useTranslations } from "@/lib/i18n/context";
 import { cn } from "@/lib/utils";
+import { apiPost } from "@/lib/api/api-fetch";
 
 export interface SelfContextAdoptOfferProps {
   /** The clarifying question the user just answered. */
@@ -39,13 +40,7 @@ export function SelfContextAdoptOffer({
 
   const adopt = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/coach/about-me/adopt", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ question, answer }),
-      });
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-      return (await res.json()).data as { adopted: boolean };
+      return apiPost<{ adopted: boolean }>("/api/coach/about-me/adopt", { question, answer });
     },
     onSuccess: (data) => {
       setSettled(data.adopted ? "adopted" : "duplicate");
diff --git a/src/components/insights/coach-panel/self-context-chips.tsx b/src/components/insights/coach-panel/self-context-chips.tsx
index 8f15556f4..6b77ac2c6 100644
--- a/src/components/insights/coach-panel/self-context-chips.tsx
+++ b/src/components/insights/coach-panel/self-context-chips.tsx
@@ -17,10 +17,12 @@
  */
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { MessageCircleQuestion, X } from "lucide-react";
+import { toast } from "sonner";
 
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { cn } from "@/lib/utils";
+import { apiDelete, apiGet } from "@/lib/api/api-fetch";
 
 export interface SelfContextChipsProps {
   /** Insert the tapped question into the composer. */
@@ -39,9 +41,7 @@ export function SelfContextChips({
   const { data } = useQuery({
     queryKey: queryKeys.coachAboutMeQuestions(),
     queryFn: async () => {
-      const res = await fetch("/api/coach/about-me/questions");
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-      return (await res.json()).data as { questions: string[] };
+      return apiGet<{ questions: string[] }>("/api/coach/about-me/questions");
     },
     staleTime: 60_000,
   });
@@ -49,17 +49,16 @@ export function SelfContextChips({
   const dismiss = useMutation({
     mutationKey: queryKeys.coachAboutMeQuestions(),
     mutationFn: async (question: string) => {
-      const res = await fetch("/api/coach/about-me/questions", {
-        method: "DELETE",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ question }),
-      });
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-      return (await res.json()).data as { questions: string[] };
+      return apiDelete<{ questions: string[] }>("/api/coach/about-me/questions", { question });
     },
     onSuccess: (next) => {
       queryClient.setQueryData(queryKeys.coachAboutMeQuestions(), next);
     },
+    // v1.16.4 — a failed dismiss used to fail silently, leaving the chip
+    // in place with no signal that the request was rejected.
+    onError: () => {
+      toast.error(t("insights.coach.selfContextChipDismissError"));
+    },
   });
 
   const questions = data?.questions ?? [];
diff --git a/src/components/insights/coach-panel/sources-rail.tsx b/src/components/insights/coach-panel/sources-rail.tsx
index 318cdc4b4..a7280373c 100644
--- a/src/components/insights/coach-panel/sources-rail.tsx
+++ b/src/components/insights/coach-panel/sources-rail.tsx
@@ -2,6 +2,7 @@
 
 import { useState } from "react";
 import { Eye, Loader2 } from "lucide-react";
+import { toast } from "sonner";
 
 import { Switch } from "@/components/ui/switch";
 import {
@@ -75,7 +76,12 @@ export function SourcesRail({ className }: SourcesRailProps) {
 
   function persist(next: CoachPrefs, marker: CoachDataCluster | "window") {
     setPending(marker);
-    save.mutate(next, { onSettled: () => setPending(null) });
+    save.mutate(next, {
+      onSettled: () => setPending(null),
+      // v1.16.4 — a failed save used to revert the switch silently once the
+      // spinner cleared; a toast names the rejection.
+      onError: () => toast.error(t("insights.coach.prefsSaveError")),
+    });
   }
 
   function toggleCluster(cluster: CoachDataCluster, next: boolean) {
diff --git a/src/components/insights/coach-panel/use-coach.ts b/src/components/insights/coach-panel/use-coach.ts
index f7ed6af13..5e787edbc 100644
--- a/src/components/insights/coach-panel/use-coach.ts
+++ b/src/components/insights/coach-panel/use-coach.ts
@@ -11,6 +11,7 @@ import type {
   CoachScope,
   CoachStreamEvent,
 } from "@/lib/ai/coach/types";
+import { apiDelete, apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.20 phase B2b — TanStack Query + SSE client for the AI Coach
@@ -34,14 +35,6 @@ const QUERY_KEYS = {
   one: (id: string) => ["coachConversation", id] as const,
 };
 
-interface ConversationsApiResponse {
-  data: CoachConversationsPage;
-}
-
-interface ConversationApiResponse {
-  data: CoachConversationDetailDTO;
-}
-
 /**
  * List of conversations for the rail. Cursor pagination is exposed via
  * `loadMore` — the rail can call it when the user scrolls past the
@@ -52,12 +45,9 @@ export function useCoachConversations(enabled = true) {
   const query = useQuery({
     queryKey: QUERY_KEYS.list(),
     queryFn: async (): Promise<CoachConversationsPage> => {
-      const res = await fetch("/api/insights/chat", {
+      return apiGet<CoachConversationsPage>("/api/insights/chat", {
         headers: { Accept: "application/json" },
       });
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-      const json = (await res.json()) as ConversationsApiResponse;
-      return json.data;
     },
     enabled,
     staleTime: 30 * 1000,
@@ -86,12 +76,9 @@ export function useCoachConversation(id: string | null) {
     queryKey: ["coachConversation", id] as const,
     queryFn: async (): Promise<CoachConversationDetailDTO> => {
       if (!id) throw new Error("missing id");
-      const res = await fetch(`/api/insights/chat/${id}`, {
+      return apiGet<CoachConversationDetailDTO>(`/api/insights/chat/${id}`, {
         headers: { Accept: "application/json" },
       });
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-      const json = (await res.json()) as ConversationApiResponse;
-      return json.data;
     },
     enabled: id !== null,
     staleTime: 60 * 1000,
@@ -106,10 +93,7 @@ export function useDeleteCoachConversation() {
   const queryClient = useQueryClient();
   return useMutation({
     mutationFn: async (id: string) => {
-      const res = await fetch(`/api/insights/chat/${id}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
+      await apiDelete(`/api/insights/chat/${id}`);
       return id;
     },
     onMutate: async (id: string) => {
@@ -210,7 +194,7 @@ export interface CoachStreamingMessage {
  * `src/app/api/insights/chat/route.ts`), but the persisted twin only
  * lands client-side after the SSE `done` frame triggers a
  * `queryClient.invalidateQueries`. The earlier render order was
- * "Thinking…" → user message → assistant reply, which Marc flagged in
+ * "Thinking…" → user message → assistant reply, which the maintainer flagged in
  * the W5 polish brief; surfacing this optimistic bubble flips the
  * order to user → "Thinking…" → assistant reply.
  *
@@ -312,7 +296,7 @@ export function useSendCoachMessage(opts: UseSendCoachMessageOptions = {}) {
       // the "Thinking…" placeholder paints. Without this the send hook
       // only exposed the streaming assistant bubble, so the first
       // thing the user saw was the placeholder followed by their own
-      // message landing on the next refetch — Marc flagged the
+      // message landing on the next refetch — the maintainer flagged the
       // order as confusing on the suggested-prompt chips.
       setOptimisticUser({
         localId: `local-${Date.now()}-${Math.random().toString(36).slice(2, 7)}`,
@@ -341,9 +325,11 @@ export function useSendCoachMessage(opts: UseSendCoachMessageOptions = {}) {
         return;
       }
 
+      // apiFetchRaw: the chat POST streams SSE — the envelope helpers
+      // would buffer and unwrap a body that never carries the envelope.
       let response: Response;
       try {
-        response = await fetch("/api/insights/chat", {
+        response = await apiFetchRaw("/api/insights/chat", {
           method: "POST",
           headers: {
             "Content-Type": "application/json",
diff --git a/src/components/insights/derived/use-derived-metric.ts b/src/components/insights/derived/use-derived-metric.ts
index abf671246..5357703eb 100644
--- a/src/components/insights/derived/use-derived-metric.ts
+++ b/src/components/insights/derived/use-derived-metric.ts
@@ -9,6 +9,7 @@ import type {
   DerivedProvenance,
 } from "@/lib/insights/derived/types";
 import type { DerivedAssessment } from "@/lib/insights/derived/derived-assessment";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.10.0 — the single TanStack Query hook for the generic derived-metric
@@ -84,13 +85,7 @@ export function useDerivedMetric<T>(
       try {
         const params = new URLSearchParams({ metric });
         if (type) params.set("type", type);
-        const res = await fetch(`/api/insights/derived?${params.toString()}`, {
-          signal: controller.signal,
-        });
-        if (!res.ok) {
-          throw new Error(`derived ${metric} request failed (${res.status})`);
-        }
-        return (await res.json()).data as DerivedMetricResponse<T>;
+        return apiGet<DerivedMetricResponse<T>>(`/api/insights/derived?${params.toString()}`, { signal: controller.signal });
       } finally {
         clearTimeout(timeoutHandle);
       }
@@ -159,14 +154,7 @@ export function useDerivedBatch(
       );
       try {
         const params = new URLSearchParams({ metrics: wireTokens.join(",") });
-        const res = await fetch(
-          `/api/insights/derived/batch?${params.toString()}`,
-          { signal: controller.signal },
-        );
-        if (!res.ok) {
-          throw new Error(`derived batch request failed (${res.status})`);
-        }
-        return (await res.json()).data as DerivedBatchResponse;
+        return apiGet<DerivedBatchResponse>(`/api/insights/derived/batch?${params.toString()}`, { signal: controller.signal });
       } finally {
         clearTimeout(timeoutHandle);
       }
diff --git a/src/components/insights/health-score-card.tsx b/src/components/insights/health-score-card.tsx
index 7d9a4f6a9..228304661 100644
--- a/src/components/insights/health-score-card.tsx
+++ b/src/components/insights/health-score-card.tsx
@@ -271,7 +271,7 @@ export function HealthScoreCard({
           accordion) instead of clumping under the disclaimer. The
           score number stays anchored at the top, the disclaimer at
           the bottom, and the card fills the row down to the
-          "Wirkt mein Medikament?" chip — closing Marc's "Karte hört
+          "Wirkt mein Medikament?" chip — closing the maintainer's "Karte hört
           bei der Trennlinie auf" report against v1.4.36. */}
       <div className="grid flex-1 grid-rows-[auto_auto_auto_auto_auto_1fr_auto] gap-3.5">
         <div className="flex items-center justify-between gap-2">
diff --git a/src/components/insights/insights-edit-mode.tsx b/src/components/insights/insights-edit-mode.tsx
index 466a99bfb..fa0fc2e54 100644
--- a/src/components/insights/insights-edit-mode.tsx
+++ b/src/components/insights/insights-edit-mode.tsx
@@ -33,6 +33,7 @@ import {
   type InsightsSectionConfig,
   type InsightsSectionId,
 } from "@/lib/insights-layout";
+import { apiDelete, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * v1.15.11 W3 — inline "Anpassen" edit mode for the customizable Insights
@@ -114,17 +115,11 @@ export function InsightsEditMode({
 
   const saveMutation = useMutation({
     mutationFn: async (next: InsightsLayout) => {
-      const res = await fetch("/api/insights/layout", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
+      return apiPut<InsightsLayout>("/api/insights/layout", {
           version: 2,
           sections: next.sections,
           tiles: next.tiles,
-        }),
-      });
-      if (!res.ok) throw new Error("save failed");
-      return (await res.json()).data as InsightsLayout;
+        });
     },
     onSuccess: (saved) => {
       // Optimistic-style settle: write the server-resolved layout into the
@@ -141,9 +136,7 @@ export function InsightsEditMode({
 
   const resetMutation = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/insights/layout", { method: "DELETE" });
-      if (!res.ok) throw new Error("reset failed");
-      return (await res.json()).data as InsightsLayout;
+      return apiDelete<InsightsLayout>("/api/insights/layout");
     },
     onSuccess: (saved) => {
       queryClient.setQueryData(queryKeys.insightsLayout(), saved);
diff --git a/src/components/insights/insights-layout-shell.tsx b/src/components/insights/insights-layout-shell.tsx
index 995bdf27c..c10e9fbf8 100644
--- a/src/components/insights/insights-layout-shell.tsx
+++ b/src/components/insights/insights-layout-shell.tsx
@@ -14,6 +14,7 @@ import { useAnalyticsQuery } from "@/lib/queries/use-analytics-query";
 import { useInsightsLayoutQuery } from "@/hooks/use-insights-layout";
 import { queryKeys } from "@/lib/query-keys";
 import type { InsightInputs } from "@/lib/insights/metric-availability";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W4 — client shell for `src/app/insights/layout.tsx`.
@@ -81,10 +82,7 @@ export function InsightsLayoutShell({ children }: { children: ReactNode }) {
   const comprehensiveQuery = useQuery({
     queryKey: queryKeys.insightsComprehensive(),
     queryFn: async () => {
-      const res = await fetch("/api/insights/comprehensive");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as ComprehensivePayload;
+      return apiGet<ComprehensivePayload>("/api/insights/comprehensive");
     },
     enabled: isAuthenticated,
   });
diff --git a/src/components/insights/insights-tab-strip.tsx b/src/components/insights/insights-tab-strip.tsx
index 7f7cb0daf..4df7cff54 100644
--- a/src/components/insights/insights-tab-strip.tsx
+++ b/src/components/insights/insights-tab-strip.tsx
@@ -43,7 +43,7 @@ import {
  * `usePathname()` decides the active pill, and the strip is mounted in
  * `src/app/insights/layout.tsx` so it persists across navigation
  * without re-rendering. The CoachDrawer is NOT mounted in this layout —
- * the drawer lives in the mother page's body only (Marc directive
+ * the drawer lives in the mother page's body only (the maintainer directive
  * 2026-05-11).
  *
  * Pills:
@@ -643,6 +643,13 @@ function InsightsTabStripImpl({
                 <Link
                   key={tab.href}
                   href={tab.href}
+                  // Full route prefetch (RSC payload incl. the dynamic
+                  // sub-page, not just the loading boundary) the moment
+                  // the pill scrolls into view. The insights sub-pages
+                  // are dynamic routes, so the default viewport prefetch
+                  // only warms `loading.tsx`; the full prefetch removes
+                  // the route-payload round-trip from the pill switch.
+                  prefetch={true}
                   aria-current={isActive ? "page" : undefined}
                   data-slot="insights-tab-strip-pill"
                   data-active={isActive ? "true" : undefined}
@@ -713,6 +720,9 @@ function InsightsTabStripImpl({
                         <li key={child.href}>
                           <Link
                             href={child.href}
+                            // Same full-prefetch contract as the flat
+                            // pills — fires when the popover opens.
+                            prefetch={true}
                             aria-current={isChildActive ? "page" : undefined}
                             data-slot="insights-tab-strip-group-item"
                             data-active={isChildActive ? "true" : undefined}
diff --git a/src/components/insights/layout-coach-fab.tsx b/src/components/insights/layout-coach-fab.tsx
index 6b4dd9d13..3ad744b93 100644
--- a/src/components/insights/layout-coach-fab.tsx
+++ b/src/components/insights/layout-coach-fab.tsx
@@ -14,6 +14,7 @@ import { useDisableCoach } from "@/hooks/use-disable-coach";
 import { queryKeys } from "@/lib/query-keys";
 
 import { useChartTooltipActive } from "./use-chart-tooltip-active";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.16.1 — the layout FAB is no longer a permanent launcher. It now
@@ -80,9 +81,7 @@ export function LayoutCoachFab() {
   const { data: status } = useQuery({
     queryKey: queryKeys.coachNudgeStatus(),
     queryFn: async (): Promise<CoachNudgeStatus> => {
-      const res = await fetch("/api/insights/coach/nudge-status");
-      if (!res.ok) throw new Error("coach-nudge-status.failed");
-      return (await res.json()).data as CoachNudgeStatus;
+      return apiGet<CoachNudgeStatus>("/api/insights/coach/nudge-status");
     },
     enabled: coachAvailable,
     staleTime: 5 * 60 * 1000,
diff --git a/src/components/insights/measurement-diversity-nudge.tsx b/src/components/insights/measurement-diversity-nudge.tsx
index 74eb1bf63..24be94321 100644
--- a/src/components/insights/measurement-diversity-nudge.tsx
+++ b/src/components/insights/measurement-diversity-nudge.tsx
@@ -12,6 +12,7 @@ import {
 import { useAuth } from "@/hooks/use-auth";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { detectMeasurementDiversity } from "@/lib/insights/measurement-diversity";
 
 /**
@@ -67,13 +68,15 @@ export function MeasurementDiversityNudge({
       params.set("limit", String(WINDOW_SIZE));
       params.set("sortBy", "measuredAt");
       params.set("sortDir", "desc");
-      const res = await fetch(`/api/measurements?${params}`);
-      if (!res.ok) return [];
-      const json = await res.json();
-      const rows = (json.data?.measurements ?? []) as Array<{
-        measuredAt: string;
-      }>;
-      return rows.map((r) => r.measuredAt);
+      try {
+        const data = await apiGet<{
+          measurements?: Array<{ measuredAt: string }>;
+        }>(`/api/measurements?${params}`);
+        return (data?.measurements ?? []).map((r) => r.measuredAt);
+      } catch {
+        // Nudge is optional — degrade to "no data", as before.
+        return [];
+      }
     },
     enabled: isAuthenticated,
     // The pattern shifts slowly — a 5-minute cache keeps the nudge calm
diff --git a/src/components/insights/metric-target-summary.tsx b/src/components/insights/metric-target-summary.tsx
index a05416cd8..296ec1b05 100644
--- a/src/components/insights/metric-target-summary.tsx
+++ b/src/components/insights/metric-target-summary.tsx
@@ -15,6 +15,7 @@ import { TargetStatusPill } from "@/components/targets/target-status-pill";
 import { TileHeader } from "@/components/insights/tile-header";
 import { useTargetAdjust } from "@/lib/insights/target-adjust-context";
 import { getTargetSourceLink } from "@/lib/targets/source-link";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.8.0 → v1.8.5 — surface the per-metric target reference panel on each
@@ -133,10 +134,7 @@ export function MetricTargetSummary({ slug }: MetricTargetSummaryProps) {
   const { data } = useQuery({
     queryKey: queryKeys.insightsTargets(),
     queryFn: async () => {
-      const res = await fetch("/api/insights/targets");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as TargetsResponse;
+      return apiGet<TargetsResponse>("/api/insights/targets");
     },
     enabled: isAuthenticated && (targetType != null || isGlucose),
   });
diff --git a/src/components/insights/mood/mood-insights-sections.tsx b/src/components/insights/mood/mood-insights-sections.tsx
index aa59d614d..c4828912d 100644
--- a/src/components/insights/mood/mood-insights-sections.tsx
+++ b/src/components/insights/mood/mood-insights-sections.tsx
@@ -95,6 +95,7 @@ import {
   MoodFactorMetricCrosstab,
   type MoodFactorMetricCrosstabRow,
 } from "./mood-factor-metric-crosstab";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.8.5 — additional Mood Insights sections.
@@ -193,10 +194,7 @@ export function MoodInsightsSections({
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.moodInsights(),
     queryFn: async () => {
-      const res = await fetch("/api/mood/insights");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as MoodInsightsResponse;
+      return apiGet<MoodInsightsResponse>("/api/mood/insights");
     },
     enabled: isAuthenticated,
     staleTime: 60_000,
diff --git a/src/components/insights/mood/mood-what-stands-out.tsx b/src/components/insights/mood/mood-what-stands-out.tsx
index 991b782c1..4ac55ffee 100644
--- a/src/components/insights/mood/mood-what-stands-out.tsx
+++ b/src/components/insights/mood/mood-what-stands-out.tsx
@@ -7,6 +7,7 @@ import { Card, CardContent, CardHeader } from "@/components/ui/card";
 import { TileHeader } from "@/components/insights/tile-header";
 import { useAuth } from "@/hooks/use-auth";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { useTranslations } from "@/lib/i18n/context";
 import {
   MoodNarrativeFeed,
@@ -44,11 +45,9 @@ export function MoodWhatStandsOut({
   const { data, isLoading, isError } = useQuery({
     queryKey: queryKeys.insightsCorrelations(),
     queryFn: async () => {
-      const res = await fetch("/api/insights/correlations");
-      // 403 = operator disabled the surface; any non-OK degrades to nothing.
-      if (!res.ok) throw new Error("unavailable");
-      const json = await res.json();
-      return json.data as CorrelationDiscoveryResponse;
+      // 403 = operator disabled the surface; any rejection (ApiError)
+      // degrades to the card's isError → render-nothing path.
+      return apiGet<CorrelationDiscoveryResponse>("/api/insights/correlations");
     },
     enabled: isAuthenticated,
     staleTime: 60_000,
diff --git a/src/components/insights/period-narrative-card.tsx b/src/components/insights/period-narrative-card.tsx
index 32a7ed59f..89647228f 100644
--- a/src/components/insights/period-narrative-card.tsx
+++ b/src/components/insights/period-narrative-card.tsx
@@ -13,6 +13,7 @@ import {
   PopoverContent,
   PopoverTrigger,
 } from "@/components/ui/popover";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.11.0 W3 — period-narrative card (Pillar P1).
@@ -59,11 +60,7 @@ interface PeriodNarrativeCardProps {
 async function fetchNarrative(
   period: NarrativePeriod,
 ): Promise<NarrativeResponse> {
-  const res = await fetch(`/api/insights/narrative?period=${period}`);
-  if (!res.ok) {
-    throw new Error(`narrative ${res.status}`);
-  }
-  return (await res.json()).data as NarrativeResponse;
+  return apiGet<NarrativeResponse>(`/api/insights/narrative?period=${period}`);
 }
 
 function ProvenanceDisclosure({
diff --git a/src/components/insights/personal-record-badge.tsx b/src/components/insights/personal-record-badge.tsx
index 14e6ecd1b..fa87dd6a4 100644
--- a/src/components/insights/personal-record-badge.tsx
+++ b/src/components/insights/personal-record-badge.tsx
@@ -29,6 +29,7 @@ import {
   TooltipTrigger,
 } from "@/components/ui/tooltip";
 import { useFormatters, useTranslations } from "@/lib/i18n/context";
+import { apiGet } from "@/lib/api/api-fetch";
 import type { MeasurementType } from "@/generated/prisma/client";
 import { cn } from "@/lib/utils";
 
@@ -76,11 +77,15 @@ export function PersonalRecordBadge({
     // `feedback_react_query_key_collision`).
     queryKey: ["personal-records", "by-metric", metricType],
     queryFn: async () => {
-      const res = await fetch(
-        `/api/personal-records?metricType=${encodeURIComponent(metricType)}`,
-      );
-      if (!res.ok) return [] as PersonalRecordRow[];
-      return ((await res.json()).data ?? []) as PersonalRecordRow[];
+      try {
+        const data = await apiGet<PersonalRecordRow[] | null>(
+          `/api/personal-records?metricType=${encodeURIComponent(metricType)}`,
+        );
+        return data ?? [];
+      } catch {
+        // The badge is decorative — degrade to "no records", as before.
+        return [] as PersonalRecordRow[];
+      }
     },
     // Per-tile data: stale-while-revalidate cadence matches the
     // dashboard's existing trend queries. 5 minutes is enough to
diff --git a/src/components/insights/recommendation-feedback.tsx b/src/components/insights/recommendation-feedback.tsx
index 8ecad561c..87f08c7b4 100644
--- a/src/components/insights/recommendation-feedback.tsx
+++ b/src/components/insights/recommendation-feedback.tsx
@@ -33,6 +33,7 @@ import { ThumbsUp, ThumbsDown, Loader2, Check } from "lucide-react";
 import { useTranslations } from "@/lib/i18n/context";
 import { useAuth } from "@/hooks/use-auth";
 import type { RecommendationFeedbackRequest } from "@/lib/validations/recommendation-feedback";
+import { ApiError, apiPost } from "@/lib/api/api-fetch";
 
 // v1.4.16 phase D reconcile (simplify F5) — re-export the canonical
 // types from the validation schema instead of hand-maintaining the
@@ -70,11 +71,6 @@ type FeedbackState =
 
 const LOCAL_STORAGE_PREFIX = "healthlog-rec-feedback";
 
-interface FeedbackEnvelope {
-  data: { id: string; createdAt: string } | null;
-  error?: string | null;
-}
-
 function localCacheKey(userId: string, recId: string, recText: string): string {
   // recText is part of the key because the server-side dedup also
   // includes it — a regeneration that rewrites the same id with new
@@ -152,24 +148,22 @@ export function RecommendationFeedback({
 
   const mutation = useMutation({
     mutationFn: async (helpful: boolean) => {
-      const res = await fetch("/api/insights/feedback", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
+      try {
+        await apiPost("/api/insights/feedback", {
           recommendationId: recId,
           recommendationText: recText,
           recommendationSeverity: recSeverity,
           metricSourceType,
           metricSourceTimeRange,
           helpful,
-        }),
-      });
-      const body = (await res.json()) as FeedbackEnvelope;
-      if (res.status === 409) {
-        return { duplicate: true, helpful } as const;
-      }
-      if (!res.ok) {
-        throw new Error(body.error ?? "feedback_failed");
+        });
+      } catch (err) {
+        // 409 = the server already holds a verdict for this rec — treat
+        // as the non-throwing duplicate outcome, exactly as before.
+        if (err instanceof ApiError && err.status === 409) {
+          return { duplicate: true, helpful } as const;
+        }
+        throw err;
       }
       return { duplicate: false, helpful } as const;
     },
diff --git a/src/components/insights/rhythm-events-card.tsx b/src/components/insights/rhythm-events-card.tsx
index d534a7876..078354999 100644
--- a/src/components/insights/rhythm-events-card.tsx
+++ b/src/components/insights/rhythm-events-card.tsx
@@ -6,6 +6,7 @@ import type { LucideIcon } from "lucide-react";
 
 import { useAuth } from "@/hooks/use-auth";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { useTranslations, useFormatters } from "@/lib/i18n/context";
 import { cn } from "@/lib/utils";
 import { SectionHeading } from "@/components/insights/section-heading";
@@ -90,10 +91,13 @@ export function RhythmEventsCard({
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.insightsRhythmEvents(),
     queryFn: async () => {
-      const res = await fetch("/api/insights/rhythm-events");
-      if (!res.ok) throw new Error(t("insights.rhythmEvents.loadError"));
-      const json = await res.json();
-      return json.data as RhythmEventsResponse;
+      try {
+        return await apiGet<RhythmEventsResponse>(
+          "/api/insights/rhythm-events",
+        );
+      } catch {
+        throw new Error(t("insights.rhythmEvents.loadError"));
+      }
     },
     enabled: enabled && isAuthenticated,
   });
diff --git a/src/components/insights/sleep-hypnogram.tsx b/src/components/insights/sleep-hypnogram.tsx
index 514cf064b..490cc3bbb 100644
--- a/src/components/insights/sleep-hypnogram.tsx
+++ b/src/components/insights/sleep-hypnogram.tsx
@@ -15,7 +15,7 @@ import { useTranslations } from "@/lib/i18n/context";
 import { STAGE_COLORS } from "./sleep-stage-stacked-bar";
 
 /**
- * v1.11.5 — last-night HYPNOGRAM (Marc directive: the phase-progression
+ * v1.11.5 — last-night HYPNOGRAM (the maintainer directive: the phase-progression
  * view). Renders one night's stage timeline as a stepped depth track —
  * Awake at the top, Deep at the base — over clock time, in the Dracula
  * stage palette reused from `sleep-stage-stacked-bar.tsx` (no token
diff --git a/src/components/insights/sleep-overview.tsx b/src/components/insights/sleep-overview.tsx
index 1685a0a67..8a4a9a824 100644
--- a/src/components/insights/sleep-overview.tsx
+++ b/src/components/insights/sleep-overview.tsx
@@ -18,6 +18,7 @@ import {
 } from "./sleep-stage-stacked-bar";
 import { SleepHypnogram, type SleepHypnogramSession } from "./sleep-hypnogram";
 import { SleepDurationChart } from "./sleep-duration-chart";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W4c — Sleep insights composition.
@@ -89,12 +90,10 @@ export function SleepOverview() {
   const nightQuery = useQuery({
     queryKey: queryKeys.sleepNight(),
     queryFn: async () => {
-      const res = await fetch("/api/sleep/night");
-      if (!res.ok) throw new Error("Failed to fetch sleep night");
-      return (await res.json()).data as {
+      return apiGet<{
         night: string | null;
         main: SleepHypnogramSession | null;
-      };
+      }>("/api/sleep/night");
     },
     enabled: isAuthenticated && totalCount > 0,
     staleTime: 60 * 1000,
diff --git a/src/components/insights/sleep-stage-stacked-bar.tsx b/src/components/insights/sleep-stage-stacked-bar.tsx
index 74ac85869..f31507094 100644
--- a/src/components/insights/sleep-stage-stacked-bar.tsx
+++ b/src/components/insights/sleep-stage-stacked-bar.tsx
@@ -20,7 +20,7 @@ import { useTranslations } from "@/lib/i18n/context";
 /**
  * v1.4.25 W4c → W3f — sleep-stage composition chart.
  *
- * Marc directive 2026-05-14: switch from "30-day average composition"
+ * The maintainer directive 2026-05-14: switch from "30-day average composition"
  * to a per-night stacked column chart so the user sees nightly stage
  * variation, not just a rolling average. Apple Health's sleep tab is
  * the visual reference — one column per night, stacks for REM / Deep /
diff --git a/src/components/insights/trend-annotation.tsx b/src/components/insights/trend-annotation.tsx
index 1a136d86d..1a69766db 100644
--- a/src/components/insights/trend-annotation.tsx
+++ b/src/components/insights/trend-annotation.tsx
@@ -19,6 +19,7 @@ import {
 } from "@/lib/insights/trend-descriptor";
 import { cn } from "@/lib/utils";
 import { CONFIDENCE_BADGE_CLASS } from "./confidence-badge";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.20 phase B3 — single-sentence AI annotation rendered directly
@@ -276,10 +277,7 @@ export function TrendDescriptorCaption({
   const moodQuery = useQuery({
     queryKey: queryKeys.moodAnalytics(),
     queryFn: async () => {
-      const res = await fetch("/api/mood/analytics");
-      if (!res.ok) throw new Error("Failed to fetch mood analytics");
-      const json = await res.json();
-      return json.data as { entries: MoodAnalyticsRow[] };
+      return apiGet<{ entries: MoodAnalyticsRow[] }>("/api/mood/analytics");
     },
     enabled: isAuthenticated && isMood,
     staleTime: 60_000,
@@ -301,10 +299,10 @@ export function TrendDescriptorCaption({
         aggregate: "daily",
         source: "rollup",
       });
-      const res = await fetch(`/api/measurements?${params}`);
-      if (!res.ok) throw new Error("Failed to fetch measurement series");
-      const json = await res.json();
-      return (json.data?.measurements ?? []) as MeasurementApiRow[];
+      const data = await apiGet<{ measurements?: MeasurementApiRow[] }>(
+        `/api/measurements?${params}`,
+      );
+      return data?.measurements ?? [];
     },
     enabled: isAuthenticated && !isMood && primaryType.length > 0,
     staleTime: 60_000,
diff --git a/src/components/insights/use-insights-advisor.ts b/src/components/insights/use-insights-advisor.ts
index 1b47147d6..78adcddea 100644
--- a/src/components/insights/use-insights-advisor.ts
+++ b/src/components/insights/use-insights-advisor.ts
@@ -10,6 +10,7 @@ import {
   type TrendAnnotations,
 } from "@/lib/ai/schema";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.16 phase D reconcile (CRITICAL C1 + C2) — shared TanStack Query
@@ -111,14 +112,17 @@ async function fetchAdvisor(
     // and enqueues an out-of-band warm on a stale / missing cache — it
     // never blocks the page-load path on the provider chain. Only the
     // user-initiated regenerate (`force`) POSTs to generate inline.
+    // apiFetchRaw: this path branches on raw status codes (422 / 429 /
+    // 503 are expected, non-throwing surfaces) — the unwrap helpers
+    // would turn them into thrown ApiErrors.
     res = options.force
-      ? await fetch("/api/insights/generate", {
+      ? await apiFetchRaw("/api/insights/generate", {
           method: "POST",
           headers: { "Content-Type": "application/json" },
           body: JSON.stringify({ force: true }),
           signal: controller.signal,
         })
-      : await fetch("/api/insights/generate", {
+      : await apiFetchRaw("/api/insights/generate", {
           method: "GET",
           signal: controller.signal,
         });
diff --git a/src/components/layout/__tests__/sidebar-nav.test.tsx b/src/components/layout/__tests__/sidebar-nav.test.tsx
index e77b05f14..0acd04ef0 100644
--- a/src/components/layout/__tests__/sidebar-nav.test.tsx
+++ b/src/components/layout/__tests__/sidebar-nav.test.tsx
@@ -15,8 +15,8 @@ vi.mock("next/navigation", () => ({
 const mockUserRef = {
   value: {
     id: "u1",
-    username: "marc",
-    email: "marc@example.com",
+    username: "testuser",
+    email: "user@example.com",
     role: "USER" as "USER" | "ADMIN",
     avatarUrl: null,
     cycleTrackingEnabled: false,
diff --git a/src/components/layout/auth-shell.tsx b/src/components/layout/auth-shell.tsx
index b534791f2..b4e9dc110 100644
--- a/src/components/layout/auth-shell.tsx
+++ b/src/components/layout/auth-shell.tsx
@@ -113,17 +113,10 @@ export function AuthShell({
   // previous `useEffect`-based redirect caused a brief dashboard flash
   // for users with `onboardingCompletedAt === null`.
 
-  // Loading state
-  if (isLoading) {
-    return (
-      <div className="flex h-dvh items-center justify-center" role="status">
-        <Loader2 className="text-primary h-6 w-6 animate-spin motion-reduce:animate-none" />
-        <span className="sr-only">{t("nav.loadingScreen")}</span>
-      </div>
-    );
-  }
-
-  // Public pages (login, register) — render without any nav
+  // Public pages (login, register) — render without any nav. Resolved
+  // BEFORE the auth-loading gate: a public page never needs the
+  // `/api/auth/me` round-trip to paint, so blocking it on `isLoading`
+  // only delayed the login form behind a spinner.
   if (isPublicPage) {
     // Long-form legal pages render edge-to-edge with their own chrome.
     if (isStandalonePublicPage) {
@@ -143,8 +136,11 @@ export function AuthShell({
     );
   }
 
-  // Not authenticated, waiting for redirect
-  if (!isAuthenticated) {
+  // Admin pages stay behind the auth gate while `/api/auth/me` is in
+  // flight: the role is unknown until the payload lands, and mounting
+  // `/admin/*` children early would fire admin queries that 403 for a
+  // non-admin before the redirect effect can move them away.
+  if (isLoading && isAdminPage) {
     return (
       <div className="flex h-dvh items-center justify-center" role="status">
         <Loader2 className="text-primary h-6 w-6 animate-spin motion-reduce:animate-none" />
@@ -153,6 +149,27 @@ export function AuthShell({
     );
   }
 
+  // Auth RESOLVED as unauthenticated — hold a spinner while the
+  // redirect effect above replaces the route with /auth/login.
+  if (!isLoading && !isAuthenticated) {
+    return (
+      <div className="flex h-dvh items-center justify-center" role="status">
+        <Loader2 className="text-primary h-6 w-6 animate-spin motion-reduce:animate-none" />
+        <span className="sr-only">{t("nav.loadingScreen")}</span>
+      </div>
+    );
+  }
+
+  // While `/api/auth/me` is still in flight the shell renders the full
+  // app chrome + children immediately (the chrome components own their
+  // null-user skeletons, pages own their data skeletons). This takes the
+  // auth round-trip off the first-paint critical path: page-level
+  // queries fire in parallel with `/api/auth/me` instead of behind it.
+  // `src/proxy.ts` has already refused cookie-less requests to
+  // protected routes, so the unauthenticated-flash window is limited to
+  // expired/invalid sessions — those resolve into the redirect branch
+  // above as soon as the 401 lands.
+
   // Onboarding page — minimal shell, no sidebar/nav
   if (isOnboardingPage) {
     return (
diff --git a/src/components/layout/sidebar-nav.tsx b/src/components/layout/sidebar-nav.tsx
index 465680541..cd778f980 100644
--- a/src/components/layout/sidebar-nav.tsx
+++ b/src/components/layout/sidebar-nav.tsx
@@ -9,7 +9,6 @@ import {
   ChevronsRight,
   Droplets,
   Home,
-  Info,
   Lightbulb,
   LogOut,
   Monitor,
diff --git a/src/components/measurements/__tests__/measurement-list-apple-health-badge.test.tsx b/src/components/measurements/__tests__/measurement-list-apple-health-badge.test.tsx
index 9eb091458..7d325e0fc 100644
--- a/src/components/measurements/__tests__/measurement-list-apple-health-badge.test.tsx
+++ b/src/components/measurements/__tests__/measurement-list-apple-health-badge.test.tsx
@@ -46,7 +46,7 @@ vi.mock("@tanstack/react-query", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "USER" },
+    user: { id: "u1", username: "testuser", role: "USER" },
     isAuthenticated: true,
     isLoading: false,
   }),
diff --git a/src/components/measurements/__tests__/measurement-list-bp-badge.test.tsx b/src/components/measurements/__tests__/measurement-list-bp-badge.test.tsx
index 9b1d09ea8..d302283a9 100644
--- a/src/components/measurements/__tests__/measurement-list-bp-badge.test.tsx
+++ b/src/components/measurements/__tests__/measurement-list-bp-badge.test.tsx
@@ -59,7 +59,7 @@ vi.mock("@tanstack/react-query", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "USER" },
+    user: { id: "u1", username: "testuser", role: "USER" },
     isAuthenticated: true,
     isLoading: false,
   }),
diff --git a/src/components/measurements/__tests__/measurement-list-empty.test.tsx b/src/components/measurements/__tests__/measurement-list-empty.test.tsx
index c209bdf4e..5ee340e74 100644
--- a/src/components/measurements/__tests__/measurement-list-empty.test.tsx
+++ b/src/components/measurements/__tests__/measurement-list-empty.test.tsx
@@ -39,7 +39,7 @@ vi.mock("@tanstack/react-query", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "USER" },
+    user: { id: "u1", username: "testuser", role: "USER" },
     isAuthenticated: true,
     isLoading: false,
   }),
diff --git a/src/components/measurements/__tests__/measurement-list-filter-select.test.tsx b/src/components/measurements/__tests__/measurement-list-filter-select.test.tsx
index 0668385f2..d2562b342 100644
--- a/src/components/measurements/__tests__/measurement-list-filter-select.test.tsx
+++ b/src/components/measurements/__tests__/measurement-list-filter-select.test.tsx
@@ -54,7 +54,7 @@ vi.mock("@tanstack/react-query", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "USER" },
+    user: { id: "u1", username: "testuser", role: "USER" },
     isAuthenticated: true,
     isLoading: false,
   }),
diff --git a/src/components/measurements/__tests__/measurement-list-locked-type.test.tsx b/src/components/measurements/__tests__/measurement-list-locked-type.test.tsx
index e3575f676..d325646ed 100644
--- a/src/components/measurements/__tests__/measurement-list-locked-type.test.tsx
+++ b/src/components/measurements/__tests__/measurement-list-locked-type.test.tsx
@@ -43,7 +43,7 @@ vi.mock("@tanstack/react-query", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "USER" },
+    user: { id: "u1", username: "testuser", role: "USER" },
     isAuthenticated: true,
     isLoading: false,
   }),
diff --git a/src/components/measurements/__tests__/measurement-list-step-grouping.test.tsx b/src/components/measurements/__tests__/measurement-list-step-grouping.test.tsx
index d30eebbb2..fdd67168f 100644
--- a/src/components/measurements/__tests__/measurement-list-step-grouping.test.tsx
+++ b/src/components/measurements/__tests__/measurement-list-step-grouping.test.tsx
@@ -58,7 +58,7 @@ vi.mock("next/navigation", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "USER" },
+    user: { id: "u1", username: "testuser", role: "USER" },
     isAuthenticated: true,
     isLoading: false,
   }),
diff --git a/src/components/measurements/measurement-form.tsx b/src/components/measurements/measurement-form.tsx
index e7705c7d6..eda1e6eb2 100644
--- a/src/components/measurements/measurement-form.tsx
+++ b/src/components/measurements/measurement-form.tsx
@@ -24,6 +24,7 @@ import { Loader2, MoreHorizontal, Plus, RotateCcw } from "lucide-react";
 import { toast } from "sonner";
 import { useTranslations } from "@/lib/i18n/context";
 import { invalidateKeys, measurementDependentKeys } from "@/lib/query-keys";
+import { ApiError, apiPost } from "@/lib/api/api-fetch";
 import { MEASUREMENT_NOTES_MAX_LENGTH } from "@/lib/validations/measurement";
 
 const MAX_COMMENT_LENGTH = MEASUREMENT_NOTES_MAX_LENGTH;
@@ -255,38 +256,16 @@ export function MeasurementForm({
           });
         }
 
-        const res = await fetch("/api/measurements", {
-          method: "POST",
-          headers: { "Content-Type": "application/json" },
-          body: JSON.stringify(batch),
-        });
-
-        const json = await res.json();
-        if (!res.ok) {
-          setError(json.error);
-          setLoading(false);
-          return;
-        }
+        await apiPost("/api/measurements", batch);
       } else {
         // Single measurement
-        const res = await fetch("/api/measurements", {
-          method: "POST",
-          headers: { "Content-Type": "application/json" },
-          body: JSON.stringify({
-            type,
-            value: parseFloat(value),
-            measuredAt: timestamp,
-            notes: notes || undefined,
-            ...(isGlucoseMode ? { glucoseContext } : {}),
-          }),
+        await apiPost("/api/measurements", {
+          type,
+          value: parseFloat(value),
+          measuredAt: timestamp,
+          notes: notes || undefined,
+          ...(isGlucoseMode ? { glucoseContext } : {}),
         });
-
-        const json = await res.json();
-        if (!res.ok) {
-          setError(json.error);
-          setLoading(false);
-          return;
-        }
       }
 
       // Reset form
@@ -298,8 +277,12 @@ export function MeasurementForm({
       await invalidateKeys(queryClient, measurementDependentKeys);
       toast.success(t("common.saved"));
       onSuccess?.();
-    } catch {
-      setError(t("measurements.saveError"));
+    } catch (err) {
+      setError(
+        err instanceof ApiError && err.message
+          ? err.message
+          : t("measurements.saveError"),
+      );
     } finally {
       setLoading(false);
     }
diff --git a/src/components/measurements/measurement-list.tsx b/src/components/measurements/measurement-list.tsx
index eb2f43901..744062778 100644
--- a/src/components/measurements/measurement-list.tsx
+++ b/src/components/measurements/measurement-list.tsx
@@ -48,7 +48,7 @@ import {
   ChevronDown,
   MoreHorizontal,
 } from "lucide-react";
-import { Fragment, useId, useState } from "react";
+import { Fragment, useCallback, useId, useState } from "react";
 import { createPortal } from "react-dom";
 import { toast } from "sonner";
 import { formatDateOrRelative, formatDateTime } from "@/lib/format";
@@ -80,6 +80,13 @@ import {
   MEASUREMENT_TYPE_ICONS as TYPE_ICONS,
   MEASUREMENT_TYPE_COLORS as TYPE_COLORS,
 } from "./measurement-list-meta";
+import {
+  ApiError,
+  apiDelete,
+  apiGet,
+  apiPost,
+  apiPut,
+} from "@/lib/api/api-fetch";
 
 /**
  * v1.4.37 W7c — cumulative HK types whose list view collapses to one
@@ -425,26 +432,49 @@ export function MeasurementList({
         params.set("limit", "366");
         params.set("offset", "0");
       }
-      const res = await fetch(`/api/measurements?${params}`);
-      if (!res.ok) throw new Error("Failed to fetch");
-      const json = await res.json();
-      return json.data as {
+      return apiGet<{
         measurements: Measurement[];
         meta: { total: number };
-      };
+      }>(`/api/measurements?${params}`);
     },
     enabled: isAuthenticated,
   });
 
+  // v1.16.4 — deletes are soft (tombstones), so the success toast can
+  // carry a real Undo: it POSTs the ids to `/api/measurements/restore`,
+  // which clears `deletedAt` and re-fires the same dependent-key bundle.
+  // Mirrors the intake-Undo pattern in `use-medication-intake.ts`.
+  const restoreMeasurements = useCallback(
+    async (ids: string[]) => {
+      try {
+        await apiPost("/api/measurements/restore", { ids });
+        await invalidateKeys(queryClient, measurementDependentKeys);
+        toast.success(t("measurements.restoredToast"));
+      } catch {
+        toast.error(t("measurements.restoreError"));
+      }
+    },
+    [queryClient, t],
+  );
+
   const deleteMutation = useMutation({
     mutationFn: async (id: string) => {
-      const res = await fetch(`/api/measurements/${id}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) throw new Error("Delete failed");
+      await apiDelete(`/api/measurements/${id}`);
     },
-    onSuccess: () => {
+    onSuccess: (_data, id) => {
       void invalidateKeys(queryClient, measurementDependentKeys);
+      toast.success(t("measurements.deletedToast"), {
+        action: {
+          label: t("common.undo"),
+          onClick: () => void restoreMeasurements([id]),
+        },
+      });
+    },
+    // v1.16.4 — a failed row delete used to fail silently (no onError
+    // handler); the edit-dialog path surfaced its own inline error but
+    // the row-level confirm had no feedback at all.
+    onError: () => {
+      toast.error(t("measurements.deleteError"));
     },
   });
 
@@ -454,20 +484,23 @@ export function MeasurementList({
   // the dashboard / insights / chart caches stay in lockstep.
   const bulkDeleteMutation = useMutation({
     mutationFn: async (ids: string[]) => {
-      const res = await fetch("/api/measurements/bulk-delete", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ ids }),
-      });
-      if (!res.ok) throw new Error("Bulk delete failed");
-      const json = (await res.json()) as { data: { deleted: number } };
-      return json.data.deleted;
+      const data = await apiPost<{ deleted: number }>(
+        "/api/measurements/bulk-delete",
+        { ids },
+      );
+      return data.deleted;
     },
-    onSuccess: async (deleted) => {
+    onSuccess: async (deleted, ids) => {
       await invalidateKeys(queryClient, measurementDependentKeys);
       clearSelection();
       toast.success(
         t("measurements.bulkDeleteSuccess", { count: String(deleted) }),
+        {
+          action: {
+            label: t("common.undo"),
+            onClick: () => void restoreMeasurements(ids),
+          },
+        },
       );
     },
     onError: () => {
@@ -517,35 +550,7 @@ export function MeasurementList({
       measuredAt: string;
       notes: string | null;
     }) => {
-      const res = await fetch(`/api/measurements/${id}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          value,
-          measuredAt,
-          notes,
-        }),
-      });
-
-      const json = (await res.json()) as {
-        error?: string;
-        meta?: { errorCode?: string };
-      };
-      if (!res.ok) {
-        // v1.4.28 FB-B1 — the PUT route now returns a 409 with
-        // `meta.errorCode === "measurement.duplicate_timestamp"` when
-        // the edit collides with an existing row's
-        // `(type, measuredAt, source, sleepStage)` tuple. Forward the
-        // code alongside the message so `onError` can pick the
-        // localised string.
-        const err = new Error(json.error ?? "Update failed") as Error & {
-          errorCode?: string;
-          status?: number;
-        };
-        err.errorCode = json.meta?.errorCode;
-        err.status = res.status;
-        throw err;
-      }
+      await apiPut(`/api/measurements/${id}`, { value, measuredAt, notes });
     },
     onSuccess: async () => {
       await invalidateKeys(queryClient, measurementDependentKeys);
@@ -553,8 +558,15 @@ export function MeasurementList({
       setEditError(null);
     },
     onError: (err) => {
-      const errWithCode = err as Error & { errorCode?: string };
-      if (errWithCode.errorCode === "measurement.duplicate_timestamp") {
+      // v1.4.28 FB-B1 — the PUT route returns a 409 with
+      // `meta.errorCode === "measurement.duplicate_timestamp"` when the
+      // edit collides with an existing row's
+      // `(type, measuredAt, source, sleepStage)` tuple. ApiError carries
+      // the envelope `meta`, so the localised string can be picked here.
+      if (
+        err instanceof ApiError &&
+        err.meta?.errorCode === "measurement.duplicate_timestamp"
+      ) {
         setEditError(t("measurements.duplicateTimestamp"));
         return;
       }
@@ -1430,10 +1442,7 @@ function DayDrillDown({
       params.set("type", type);
       params.set("dayKey", dayKey);
       params.set("sortDir", "asc");
-      const res = await fetch(`/api/measurements?${params}`);
-      if (!res.ok) throw new Error("Failed to fetch drill-down");
-      const json = await res.json();
-      return json.data as { measurements: Measurement[] };
+      return apiGet<{ measurements: Measurement[] }>(`/api/measurements?${params}`);
     },
     enabled: isAuthenticated,
     // The drill-down is per-day — once fetched it rarely needs to
diff --git a/src/components/medications/DrugLevelChart.tsx b/src/components/medications/DrugLevelChart.tsx
index bc3d26c59..a2c523862 100644
--- a/src/components/medications/DrugLevelChart.tsx
+++ b/src/components/medications/DrugLevelChart.tsx
@@ -49,6 +49,7 @@ import {
 
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import {
   computeOneCompartment,
   type DoseEvent,
@@ -127,10 +128,13 @@ export function DrugLevelChart({ medication, asOf }: DrugLevelChartProps) {
     useQuery<Glp1DetailsResponse | null>({
       queryKey: queryKeys.medicationGlp1Details(medication.id),
       queryFn: async () => {
-        const res = await fetch(`/api/medications/${medication.id}/glp1`);
-        if (!res.ok) return null;
-        const json = await res.json();
-        return json.data as Glp1DetailsResponse;
+        try {
+          return await apiGet<Glp1DetailsResponse>(
+            `/api/medications/${medication.id}/glp1`,
+          );
+        } catch {
+          return null;
+        }
       },
       enabled: !!drugId,
       staleTime: 60 * 1000,
@@ -139,12 +143,13 @@ export function DrugLevelChart({ medication, asOf }: DrugLevelChartProps) {
   const { data: intakeEnvelope, isLoading: intakeLoading } = useQuery({
     queryKey: queryKeys.medicationIntakeDrugLevelChart(medication.id),
     queryFn: async () => {
-      const res = await fetch(
-        `/api/medications/${medication.id}/intake?limit=20&sortBy=takenAt&sortDir=desc`,
-      );
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as { events: IntakeEvent[] };
+      try {
+        return await apiGet<{ events: IntakeEvent[] }>(
+          `/api/medications/${medication.id}/intake?limit=20&sortBy=takenAt&sortDir=desc`,
+        );
+      } catch {
+        return null;
+      }
     },
     enabled: !!drugId,
     staleTime: 60 * 1000,
diff --git a/src/components/medications/ResearchModeAcknowledgmentDialog.tsx b/src/components/medications/ResearchModeAcknowledgmentDialog.tsx
index f74419148..6a4f86557 100644
--- a/src/components/medications/ResearchModeAcknowledgmentDialog.tsx
+++ b/src/components/medications/ResearchModeAcknowledgmentDialog.tsx
@@ -23,7 +23,7 @@
  *     re-fetches the research-mode state and renders the toggle in
  *     the new state.
  *
- * Copy direction (Marc-Voice, English, no AI/phase/wave mentions):
+ * Copy direction (project-voice, English, no AI/phase/wave mentions):
  *   - "What this is" — single-paragraph framing: the chart is an
  *     estimate from EMA-published population PK.
  *   - "What this isn't" — explicit boundary: not a measurement, not
@@ -46,6 +46,7 @@ import { ResponsiveSheet } from "@/components/ui/responsive-sheet";
 import { Button } from "@/components/ui/button";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiPost } from "@/lib/api/api-fetch";
 
 export interface ResearchModeAcknowledgmentDialogProps {
   open: boolean;
@@ -77,18 +78,14 @@ export function ResearchModeAcknowledgmentDialog({
 
   const mutation = useMutation({
     mutationFn: async (version: string) => {
-      const res = await fetch("/api/auth/me/research-mode", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ acknowledged: true, version }),
-      });
-      const json = await res.json().catch(() => ({}));
-      if (!res.ok) {
-        const code =
-          typeof json?.error === "string" ? json.error : `http-${res.status}`;
-        throw new Error(code);
-      }
-      return json?.data ?? null;
+      // ApiError.message carries the envelope `error` string verbatim, so
+      // the stale-version code below still matches on `err.message`.
+      return (
+        (await apiPost("/api/auth/me/research-mode", {
+          acknowledged: true,
+          version,
+        })) ?? null
+      );
     },
     onSuccess: () => {
       setErrorMessage(null);
diff --git a/src/components/medications/SideEffectsSection.tsx b/src/components/medications/SideEffectsSection.tsx
index 7dc75806c..b21ee6d25 100644
--- a/src/components/medications/SideEffectsSection.tsx
+++ b/src/components/medications/SideEffectsSection.tsx
@@ -3,6 +3,7 @@
 import { useId, useMemo, useState } from "react";
 import { createPortal } from "react-dom";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { toast } from "sonner";
 import { Loader2, Plus, Trash2 } from "lucide-react";
 
 import { Button } from "@/components/ui/button";
@@ -31,6 +32,7 @@ import {
   severityLikertLabel,
 } from "@/lib/medications/side-effects/taxonomy";
 import { MedicationDetailSection } from "@/components/medications/medication-detail-section";
+import { apiDelete, apiPost } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W19d — GLP-1 side-effect section for the medication detail
@@ -146,18 +148,10 @@ export function SideEffectsSection({ medicationId }: SideEffectsSectionProps) {
       // from the wire payload. The server derives it from the entry
       // via `categoryForEntry`. Backwards-compatible with older
       // clients during the cut window (route accepts both shapes).
-      const res = await fetch(`/api/medications/${medicationId}/side-effects`, {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(payload),
-      });
-      if (!res.ok) {
-        const body = (await res.json().catch(() => ({}))) as {
-          error?: string;
-        };
-        throw new Error(body.error ?? "Failed to log side effect");
-      }
-      return (await res.json()).data as SideEffectRow;
+      return apiPost<SideEffectRow>(
+        `/api/medications/${medicationId}/side-effects`,
+        payload,
+      );
     },
     onSuccess: () => {
       void queryClient.invalidateQueries({ queryKey: listKey });
@@ -166,16 +160,17 @@ export function SideEffectsSection({ medicationId }: SideEffectsSectionProps) {
 
   const deleteMutation = useMutation({
     mutationFn: async (logId: string) => {
-      const res = await fetch(
-        `/api/medications/${medicationId}/side-effects/${logId}`,
-        { method: "DELETE" },
-      );
-      if (!res.ok) throw new Error("Failed to delete entry");
+      await apiDelete(`/api/medications/${medicationId}/side-effects/${logId}`);
       return true;
     },
     onSuccess: () => {
       void queryClient.invalidateQueries({ queryKey: listKey });
     },
+    // v1.16.4 — a failed delete used to fail silently, leaving the row
+    // in place with no signal that the request was rejected.
+    onError: () => {
+      toast.error(t("medications.sideEffects.deleteError"));
+    },
   });
 
   const items = data?.items ?? [];
diff --git a/src/components/medications/__tests__/ResearchModeAcknowledgmentDialog.test.tsx b/src/components/medications/__tests__/ResearchModeAcknowledgmentDialog.test.tsx
index eaaa9440d..9b6d70da1 100644
--- a/src/components/medications/__tests__/ResearchModeAcknowledgmentDialog.test.tsx
+++ b/src/components/medications/__tests__/ResearchModeAcknowledgmentDialog.test.tsx
@@ -145,7 +145,7 @@ describe("<ResearchModeAcknowledgmentDialog>", () => {
     expect(html).toContain("Sources");
 
     // Cited regulatory references must appear verbatim in the
-    // user-facing copy (Marc-Voice + research §11 + §12.4).
+    // user-facing copy (project-voice + research §11 + §12.4).
     expect(html).toContain("2017/745");
     expect(html).toContain("MDCG 2021-24");
     // Peer-reviewed citation.
@@ -172,6 +172,8 @@ describe("<ResearchModeAcknowledgmentDialog>", () => {
     const fetchMock = vi.fn().mockResolvedValue({
       ok: true,
       json: async () => ({ data: { enabled: true } }),
+      // The apiFetch wrapper reads the envelope via `text()`.
+      text: async () => JSON.stringify({ data: { enabled: true } }),
     });
     vi.stubGlobal("fetch", fetchMock);
 
diff --git a/src/components/medications/__tests__/card-parts.test.tsx b/src/components/medications/__tests__/card-parts.test.tsx
index 8619ad4ca..20bb355ba 100644
--- a/src/components/medications/__tests__/card-parts.test.tsx
+++ b/src/components/medications/__tests__/card-parts.test.tsx
@@ -373,7 +373,7 @@ describe("streak-token parity — generic vs GLP-1 card", () => {
 /**
  * v1.15.18 — the ONE shared `<MedicationCardBody>` both cards render. These
  * tests pin that the card surface is a CONSTANT neutral surface — dose status
- * is never expressed as a background / border tint (Marc, recurring) — while
+ * is never expressed as a background / border tint (the maintainer, recurring) — while
  * status is still surfaced via the discreet top line / pill, plus the
  * structural identity that makes the two variants impossible to diverge.
  */
@@ -406,7 +406,7 @@ describe("medication card body — shared shell + dose-state presentation", () =
   }
 
   it("never tints the card surface when the dose is in its take-window", () => {
-    // Marc (recurring): the whole card washing green reads as "take it now"
+    // The maintainer (recurring): the whole card washing green reads as "take it now"
     // and is a permanent removal. The take-window status survives ONLY as the
     // discreet "Take now" pill, never as a card background / ring tint.
     const html = renderBody("on_time_window");
diff --git a/src/components/medications/__tests__/intake-history-list-v2.test.tsx b/src/components/medications/__tests__/intake-history-list-v2.test.tsx
index 1b1352f71..3f6ff3a27 100644
--- a/src/components/medications/__tests__/intake-history-list-v2.test.tsx
+++ b/src/components/medications/__tests__/intake-history-list-v2.test.tsx
@@ -148,7 +148,7 @@ describe("<IntakeHistoryListV2> — populated rows", () => {
   });
 
   it("renders the taken row with a green Check chip and the skipped row with an outline SkipForward chip", () => {
-    // v1.4.37 W3 — guards the regression Marc reported on 2026-05-17:
+    // v1.4.37 W3 — guards the regression the maintainer reported on 2026-05-17:
     // before the fix, every row used the same secondary badge with the
     // "Eingenommen" label regardless of skipped status. The chip must
     // surface a distinct icon + label per branch and never label a
@@ -198,7 +198,7 @@ describe("<IntakeHistoryListV2> — populated rows", () => {
   });
 
   it("renders the skipped chip in German without leaking the Eingenommen label", () => {
-    // v1.4.37 W3 — UAT echo. Marc reported a German row labelled
+    // v1.4.37 W3 — UAT echo. The maintainer reported a German row labelled
     // both "übersprungen" and "eingenommen". The fix means a
     // skipped-only fixture renders "Übersprungen" exactly once and
     // "Eingenommen" zero times.
diff --git a/src/components/medications/__tests__/use-medication-intake.test.ts b/src/components/medications/__tests__/use-medication-intake.test.ts
index 48274afe0..72466325a 100644
--- a/src/components/medications/__tests__/use-medication-intake.test.ts
+++ b/src/components/medications/__tests__/use-medication-intake.test.ts
@@ -108,6 +108,10 @@ describe("runRecordIntake — shared C1 failure toast + C2 Undo", () => {
       vi.fn().mockResolvedValue({
         ok: true,
         json: vi.fn().mockResolvedValue({ data: { id: "evt-99" } }),
+        // The apiFetch wrapper reads the envelope via `text()`.
+        text: vi
+          .fn()
+          .mockResolvedValue(JSON.stringify({ data: { id: "evt-99" } })),
       }),
     );
     const undoIntake = vi.fn();
@@ -144,6 +148,7 @@ describe("runRecordIntake — shared C1 failure toast + C2 Undo", () => {
     const fetchMock = vi.fn().mockResolvedValue({
       ok: true,
       json: vi.fn().mockResolvedValue({ data: { id: "evt-am" } }),
+      text: vi.fn().mockResolvedValue(JSON.stringify({ data: { id: "evt-am" } })),
     });
     vi.stubGlobal("fetch", fetchMock);
 
@@ -172,6 +177,7 @@ describe("runRecordIntake — shared C1 failure toast + C2 Undo", () => {
     const fetchMock = vi.fn().mockResolvedValue({
       ok: true,
       json: vi.fn().mockResolvedValue({ data: { id: "evt" } }),
+      text: vi.fn().mockResolvedValue(JSON.stringify({ data: { id: "evt" } })),
     });
     vi.stubGlobal("fetch", fetchMock);
 
@@ -239,6 +245,7 @@ describe("runRecordIntake — shared C1 failure toast + C2 Undo", () => {
       vi.fn().mockResolvedValue({
         ok: true,
         json: vi.fn().mockResolvedValue({ data: {} }),
+        text: vi.fn().mockResolvedValue(JSON.stringify({ data: {} })),
       }),
     );
 
@@ -258,7 +265,11 @@ describe("runRecordIntake — shared C1 failure toast + C2 Undo", () => {
 
 describe("runLogIntake — manual backdated intake from the Add choice", () => {
   it("posts a backdated takenAt against the medication's intake route and returns true", async () => {
-    const fetchMock = vi.fn().mockResolvedValue({ ok: true, json: vi.fn() });
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      json: vi.fn(),
+      text: vi.fn().mockResolvedValue(""),
+    });
     vi.stubGlobal("fetch", fetchMock);
     const queryClient = fakeQueryClient();
 
@@ -284,7 +295,11 @@ describe("runLogIntake — manual backdated intake from the Add choice", () => {
   });
 
   it("threads scheduledFor (the chosen slot) so the write routes through the canonical slot upsert", async () => {
-    const fetchMock = vi.fn().mockResolvedValue({ ok: true, json: vi.fn() });
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      json: vi.fn(),
+      text: vi.fn().mockResolvedValue(""),
+    });
     vi.stubGlobal("fetch", fetchMock);
 
     await runLogIntake({
@@ -307,7 +322,11 @@ describe("runLogIntake — manual backdated intake from the Add choice", () => {
   });
 
   it("omits takenAt on a skipped log and shows the skipped toast", async () => {
-    const fetchMock = vi.fn().mockResolvedValue({ ok: true, json: vi.fn() });
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      json: vi.fn(),
+      text: vi.fn().mockResolvedValue(""),
+    });
     vi.stubGlobal("fetch", fetchMock);
 
     await runLogIntake({
@@ -351,7 +370,10 @@ describe("runLogIntake — manual backdated intake from the Add choice", () => {
 
 describe("runUndoIntake — shared soft-delete", () => {
   it("reverts via DELETE and confirms on success", async () => {
-    const fetchMock = vi.fn().mockResolvedValue({ ok: true });
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      text: vi.fn().mockResolvedValue(""),
+    });
     vi.stubGlobal("fetch", fetchMock);
     const queryClient = fakeQueryClient();
 
diff --git a/src/components/medications/card-parts/medication-card-body.tsx b/src/components/medications/card-parts/medication-card-body.tsx
index 6566c1c9a..a0850c332 100644
--- a/src/components/medications/card-parts/medication-card-body.tsx
+++ b/src/components/medications/card-parts/medication-card-body.tsx
@@ -142,7 +142,7 @@ export function MedicationCardBody({
   return (
     <Card
       // The card surface is a constant neutral surface — dose status is never
-      // expressed as a background / border tint (Marc, recurring): only the
+      // expressed as a background / border tint (the maintainer, recurring): only the
       // discreet status line / pill below communicates take-now / overdue.
       className={cn("h-full", active ? "" : "opacity-60")}
     >
diff --git a/src/components/medications/detail/MedicationDetailTabs.tsx b/src/components/medications/detail/MedicationDetailTabs.tsx
index c77419b99..d9bc5ebda 100644
--- a/src/components/medications/detail/MedicationDetailTabs.tsx
+++ b/src/components/medications/detail/MedicationDetailTabs.tsx
@@ -74,6 +74,7 @@ import { MedicationWizardDialog } from "@/components/medications/wizard/Medicati
 import { parseScheduleRecurrence } from "@/lib/medication-schedule";
 import { useQuery } from "@tanstack/react-query";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { useTranslations, useFormatters } from "@/lib/i18n/context";
 import type { MedicationPayload } from "@/components/medications/wizard/wizard-payload";
 import type { ComplianceDisplay } from "@/lib/analytics/compliance";
@@ -280,13 +281,15 @@ export function MedicationDetailTabs({
   const { data: compliance } = useQuery({
     queryKey: queryKeys.medicationCompliance(id),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${id}/compliance`);
-      if (!res.ok) return null;
-      return (await res.json()).data as {
-        compliance7?: { rate: number; streak: number };
-        compliance30?: { rate: number };
-        complianceDisplay?: ComplianceDisplay;
-      };
+      try {
+        return await apiGet<{
+          compliance7?: { rate: number; streak: number };
+          compliance30?: { rate: number };
+          complianceDisplay?: ComplianceDisplay;
+        }>(`/api/medications/${id}/compliance`);
+      } catch {
+        return null;
+      }
     },
     enabled: activeTab === "uebersicht",
     staleTime: 30_000,
@@ -306,15 +309,17 @@ export function MedicationDetailTabs({
   const { data: inventory } = useQuery({
     queryKey: queryKeys.medicationInventory(id),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${id}/inventory`);
-      if (!res.ok) return null;
-      return (await res.json()).data as {
-        items: Array<{
-          state: "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
-          dosesTotal: number;
-          dosesRemaining: number;
-        }>;
-      } | null;
+      try {
+        return await apiGet<{
+          items: Array<{
+            state: "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
+            dosesTotal: number;
+            dosesRemaining: number;
+          }>;
+        } | null>(`/api/medications/${id}/inventory`);
+      } catch {
+        return null;
+      }
     },
     enabled: activeTab === "uebersicht",
     staleTime: 30_000,
@@ -787,12 +792,14 @@ function ComplianceGatedDangerZone({
         offset: String(params.offset),
         status: params.status,
       });
-      const res = await fetch(
-        `/api/medications/${medicationId}/intake?${search.toString()}`,
-      );
-      if (!res.ok) return 0;
-      const json = await res.json();
-      return (json.data?.meta?.total ?? 0) as number;
+      try {
+        const data = await apiGet<{ meta?: { total?: number } }>(
+          `/api/medications/${medicationId}/intake?${search.toString()}`,
+        );
+        return data?.meta?.total ?? 0;
+      } catch {
+        return 0;
+      }
     },
     staleTime: 30_000,
   });
diff --git a/src/components/medications/dose-history-add-dialog.tsx b/src/components/medications/dose-history-add-dialog.tsx
index b758d0e5e..3a03865b8 100644
--- a/src/components/medications/dose-history-add-dialog.tsx
+++ b/src/components/medications/dose-history-add-dialog.tsx
@@ -7,7 +7,7 @@
  * medication whose ledger the user is editing, so it drops the medication
  * picker and adds the late-take nudge.
  *
- * The nudge (Marc decision): when the picked `takenAt` falls JUST OUTSIDE a
+ * The nudge (the maintainer decision): when the picked `takenAt` falls JUST OUTSIDE a
  * slot's on-time window — close enough that it is plausibly that dose, but
  * past the ±1h default band — the dialog offers "diesem Slot zuordnen?". On
  * accept the write carries `forceSlotInstant` (the nearest slot's instant on
@@ -36,6 +36,7 @@ import { Input } from "@/components/ui/input";
 import { Switch } from "@/components/ui/switch";
 import { useTranslations } from "@/lib/i18n/context";
 import { invalidateKeys, medicationDependentKeys } from "@/lib/query-keys";
+import { apiPost } from "@/lib/api/api-fetch";
 import type { QueryKey } from "@tanstack/react-query";
 import type { LedgerSchedule } from "@/components/medications/dose-history-ledger";
 
@@ -163,19 +164,10 @@ export function LedgerAddDialog({
           body.forceSlotInstant = nearest.instant.toISOString();
         }
       }
-      const res = await fetch(`/api/medications/${medicationId}/intake`, {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      if (!res.ok) {
-        // A 422 here is the force-slot guard rejecting a non-slot instant;
-        // surface it rather than silently dropping the dose.
-        toast.error(
-          t("medications.intakeToastFailed", { name: medicationName }),
-        );
-        return;
-      }
+      // A 422 here is the force-slot guard rejecting a non-slot instant;
+      // apiPost throws so the catch below surfaces it rather than silently
+      // dropping the dose.
+      await apiPost(`/api/medications/${medicationId}/intake`, body);
       toast.success(
         t(
           skipped
@@ -219,69 +211,82 @@ export function LedgerAddDialog({
           </DialogDescription>
         </DialogHeader>
 
-        <div className="space-y-3">
-          <div className="space-y-2">
-            <Label htmlFor="ledger-add-taken-at">
-              {t("medications.detail.verlauf.addDialog.takenAtLabel")}
-            </Label>
-            <Input
-              id="ledger-add-taken-at"
-              type="datetime-local"
-              value={takenAt}
-              max={toDateTimeLocal(new Date())}
-              onChange={(e) => setTakenAt(e.target.value)}
-              disabled={skipped}
-            />
+        {/* v1.16.4 — a real form so Enter in the datetime field submits;
+            the buttons carry explicit types so cancel never submits. The
+            nested nudge dialog renders through a portal, so its buttons
+            never land inside this form. */}
+        <form
+          className="space-y-4"
+          onSubmit={(e) => {
+            e.preventDefault();
+            submit();
+          }}
+        >
+          <div className="space-y-3">
+            <div className="space-y-2">
+              <Label htmlFor="ledger-add-taken-at">
+                {t("medications.detail.verlauf.addDialog.takenAtLabel")}
+              </Label>
+              <Input
+                id="ledger-add-taken-at"
+                type="datetime-local"
+                value={takenAt}
+                max={toDateTimeLocal(new Date())}
+                onChange={(e) => setTakenAt(e.target.value)}
+                disabled={skipped}
+              />
+            </div>
+
+            <label
+              htmlFor="ledger-add-skipped"
+              className="flex items-center justify-between gap-3"
+            >
+              <span className="text-sm font-medium">
+                {t("medications.detail.verlauf.addDialog.skippedLabel")}
+              </span>
+              <Switch
+                id="ledger-add-skipped"
+                checked={skipped}
+                onCheckedChange={setSkipped}
+              />
+            </label>
+
+            {/* A near-miss take previews where it will land before the user
+              commits — calm, not alarming. */}
+            {!skipped && classification === "nudge" && nearest && (
+              <p
+                className="text-muted-foreground text-xs"
+                data-slot="ledger-add-nudge-hint"
+              >
+                {t("medications.detail.verlauf.addDialog.nudgeHint", {
+                  slot: nearest.slotHm,
+                })}
+              </p>
+            )}
           </div>
 
-          <label
-            htmlFor="ledger-add-skipped"
-            className="flex items-center justify-between gap-3"
-          >
-            <span className="text-sm font-medium">
-              {t("medications.detail.verlauf.addDialog.skippedLabel")}
-            </span>
-            <Switch
-              id="ledger-add-skipped"
-              checked={skipped}
-              onCheckedChange={setSkipped}
-            />
-          </label>
-
-          {/* A near-miss take previews where it will land before the user
-              commits — calm, not alarming. */}
-          {!skipped && classification === "nudge" && nearest && (
-            <p
-              className="text-muted-foreground text-xs"
-              data-slot="ledger-add-nudge-hint"
+          <DialogFooter>
+            <Button
+              type="button"
+              variant="outline"
+              onClick={() => onOpenChange(false)}
+              disabled={busy}
             >
-              {t("medications.detail.verlauf.addDialog.nudgeHint", {
-                slot: nearest.slotHm,
-              })}
-            </p>
-          )}
-        </div>
-
-        <DialogFooter>
-          <Button
-            variant="outline"
-            onClick={() => onOpenChange(false)}
-            disabled={busy}
-          >
-            {t("medications.detail.verlauf.addDialog.cancel")}
-          </Button>
-          <Button
-            onClick={submit}
-            disabled={busy}
-            aria-busy={busy || undefined}
-            data-slot="ledger-add-submit"
-          >
-            {busy && (
-              <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-            )}
-            {t("medications.detail.verlauf.addDialog.submit")}
-          </Button>
-        </DialogFooter>
+              {t("medications.detail.verlauf.addDialog.cancel")}
+            </Button>
+            <Button
+              type="submit"
+              disabled={busy}
+              aria-busy={busy || undefined}
+              data-slot="ledger-add-submit"
+            >
+              {busy && (
+                <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+              )}
+              {t("medications.detail.verlauf.addDialog.submit")}
+            </Button>
+          </DialogFooter>
+        </form>
 
         {/* The "diesem Slot zuordnen?" nudge — pin onto the slot, or keep the
             take as a standalone ad-hoc entry. */}
diff --git a/src/components/medications/dose-history-ledger.tsx b/src/components/medications/dose-history-ledger.tsx
index f8e423d85..875f561c4 100644
--- a/src/components/medications/dose-history-ledger.tsx
+++ b/src/components/medications/dose-history-ledger.tsx
@@ -96,6 +96,7 @@ import {
   type LedgerPayload,
   type LedgerRow,
 } from "@/components/medications/dose-history-ledger-compute";
+import { apiDelete, apiGet, apiPost, apiPut } from "@/lib/api/api-fetch";
 
 const DAY_MS = 24 * 60 * 60 * 1000;
 
@@ -190,11 +191,7 @@ export function DoseHistoryLedger({
     queryKey,
     queryFn: async () => {
       const search = new URLSearchParams({ from: fromIso, to: toIso });
-      const res = await fetch(
-        `/api/medications/${medicationId}/dose-history?${search.toString()}`,
-      );
-      if (!res.ok) throw new Error("dose_history_failed");
-      return (await res.json()).data as LedgerPayload;
+      return apiGet<LedgerPayload>(`/api/medications/${medicationId}/dose-history?${search.toString()}`);
     },
     staleTime: 15_000,
   });
@@ -245,37 +242,21 @@ export function DoseHistoryLedger({
       }
 
       try {
-        const res = await fetch(`/api/medications/${medicationId}/intake`, {
-          method: "POST",
-          headers: { "Content-Type": "application/json" },
-          // Pin the displayed slot so the server marks THAT dose (the canonical
-          // slot upsert), not a now-snap to the nearest one.
-          body: JSON.stringify(
-            action === "skipped"
-              ? { skipped: true, scheduledFor: row.at }
-              : {
-                  skipped: false,
-                  scheduledFor: row.at,
-                  takenAt: new Date().toISOString(),
-                },
-          ),
-        });
-        if (!res.ok) {
-          if (prev) queryClient.setQueryData(queryKey, prev);
-          toast.error(
-            t("medications.intakeToastFailed", { name: medicationName }),
-          );
-          return;
-        }
-        // The POST returns the created event; its id drives the Undo
-        // affordance (the same soft-delete route the cards use).
-        let eventId: string | undefined;
-        try {
-          const json = await res.json();
-          eventId = json?.data?.id as string | undefined;
-        } catch {
-          /* dose recorded; the body is best-effort for the id */
-        }
+        // Pin the displayed slot so the server marks THAT dose (the canonical
+        // slot upsert), not a now-snap to the nearest one. The POST returns
+        // the created event; its id drives the Undo affordance (the same
+        // soft-delete route the cards use).
+        const created = await apiPost<{ id?: string } | undefined>(
+          `/api/medications/${medicationId}/intake`,
+          action === "skipped"
+            ? { skipped: true, scheduledFor: row.at }
+            : {
+                skipped: false,
+                scheduledFor: row.at,
+                takenAt: new Date().toISOString(),
+              },
+        );
+        const eventId: string | undefined = created?.id;
         toast.success(
           t(
             action === "skipped"
@@ -333,18 +314,10 @@ export function DoseHistoryLedger({
               takenAt: intake.scheduledFor ?? new Date().toISOString(),
             }
           : { skipped: true, takenAt: null };
-        const res = await fetch(
+        await apiPut(
           `/api/medications/${medicationId}/intake/${intake.id}`,
-          {
-            method: "PUT",
-            headers: { "Content-Type": "application/json" },
-            body: JSON.stringify(body),
-          },
+          body,
         );
-        if (!res.ok) {
-          toast.error(t("medications.detail.intake.edit.failed"));
-          return;
-        }
         await invalidateKeys(queryClient, [
           ...medicationDependentKeys,
           queryKey,
@@ -366,18 +339,9 @@ export function DoseHistoryLedger({
   const setAttribution = useCallback(
     async (eventId: string, slotAtIso: string | null) => {
       try {
-        const res = await fetch(
-          `/api/medications/${medicationId}/intake/${eventId}`,
-          {
-            method: "PUT",
-            headers: { "Content-Type": "application/json" },
-            body: JSON.stringify({ forceSlotInstant: slotAtIso }),
-          },
-        );
-        if (!res.ok) {
-          toast.error(t("medications.detail.intake.edit.failed"));
-          return;
-        }
+        await apiPut(`/api/medications/${medicationId}/intake/${eventId}`, {
+          forceSlotInstant: slotAtIso,
+        });
         toast.success(
           t(
             slotAtIso
@@ -401,14 +365,7 @@ export function DoseHistoryLedger({
     const id = pendingDeleteId;
     setPendingDeleteId(null);
     try {
-      const res = await fetch(
-        `/api/medications/${medicationId}/intake/${id}`,
-        { method: "DELETE" },
-      );
-      if (!res.ok) {
-        toast.error(t("medications.detail.intake.deleteRow.failed"));
-        return;
-      }
+      await apiDelete(`/api/medications/${medicationId}/intake/${id}`);
       toast.success(t("medications.detail.intake.deleteRow.toast"));
       await invalidateKeys(queryClient, [...medicationDependentKeys, queryKey]);
     } catch {
diff --git a/src/components/medications/dose-strength-curve.tsx b/src/components/medications/dose-strength-curve.tsx
index ca25ea1d4..47875ead2 100644
--- a/src/components/medications/dose-strength-curve.tsx
+++ b/src/components/medications/dose-strength-curve.tsx
@@ -44,6 +44,7 @@ import {
 
 import { useTranslations, useFormatters } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 import { prefersReducedMotion } from "@/lib/charts/reduced-motion";
 import { MedicationDetailSection } from "@/components/medications/medication-detail-section";
 
@@ -115,10 +116,13 @@ export function DoseStrengthCurve({
   const { data: details, isLoading } = useQuery<Glp1DetailsResponse | null>({
     queryKey: queryKeys.medicationGlp1Details(medicationId),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medicationId}/glp1`);
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as Glp1DetailsResponse;
+      try {
+        return await apiGet<Glp1DetailsResponse>(
+          `/api/medications/${medicationId}/glp1`,
+        );
+      } catch {
+        return null;
+      }
     },
     staleTime: 60 * 1000,
   });
diff --git a/src/components/medications/glp1-medication-card.tsx b/src/components/medications/glp1-medication-card.tsx
index aabb41e1a..099fc83ba 100644
--- a/src/components/medications/glp1-medication-card.tsx
+++ b/src/components/medications/glp1-medication-card.tsx
@@ -15,6 +15,7 @@ import {
   medicationDependentKeys,
   queryKeys,
 } from "@/lib/query-keys";
+import { apiGet, apiPost } from "@/lib/api/api-fetch";
 import { formatDateTime, formatTime } from "@/lib/format";
 import { getMedicationCategoryLabel } from "@/lib/medications/category-label";
 import { type InjectionSiteKey } from "@/lib/medications/injection-sites";
@@ -204,10 +205,13 @@ export function Glp1MedicationCard({
   const { data: compliance } = useQuery({
     queryKey: queryKeys.medicationCompliance(medication.id),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medication.id}/compliance`);
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as ComplianceData;
+      try {
+        return await apiGet<ComplianceData>(
+          `/api/medications/${medication.id}/compliance`,
+        );
+      } catch {
+        return null;
+      }
     },
     // v1.15.20 — same 5-minute window as the generic card: dose actions
     // invalidate the key explicitly, so a short staleTime only re-fired
@@ -221,10 +225,13 @@ export function Glp1MedicationCard({
   const { data: thresholds } = useQuery({
     queryKey: queryKeys.settingsReminderThresholds(),
     queryFn: async () => {
-      const res = await fetch("/api/settings/reminder-thresholds");
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as { lateMinutes: number; missedMinutes: number };
+      try {
+        return await apiGet<{ lateMinutes: number; missedMinutes: number }>(
+          "/api/settings/reminder-thresholds",
+        );
+      } catch {
+        return null;
+      }
     },
     staleTime: 5 * 60 * 1000,
   });
@@ -235,10 +242,13 @@ export function Glp1MedicationCard({
   const { data: details } = useQuery({
     queryKey: queryKeys.medicationGlp1Details(medication.id),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medication.id}/glp1`);
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as DetailsResponse;
+      try {
+        return await apiGet<DetailsResponse>(
+          `/api/medications/${medication.id}/glp1`,
+        );
+      } catch {
+        return null;
+      }
     },
     staleTime: 60 * 1000,
   });
@@ -257,14 +267,15 @@ export function Glp1MedicationCard({
     // v1.11.5 — keep the dialog open until the PATCH resolves. On failure
     // surface a toast and re-throw so the dialog stays mounted with the
     // chosen site instead of dismissing as though the site had been saved.
-    const res = await fetch("/api/medications/intake", {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ intakeId, status: "taken", injectionSite: site }),
-    });
-    if (!res.ok) {
+    try {
+      await apiPost("/api/medications/intake", {
+        intakeId,
+        status: "taken",
+        injectionSite: site,
+      });
+    } catch (err) {
       toast.error(t("medications.logInjectionSiteSaveFailed"));
-      throw new Error("injection-site PATCH failed");
+      throw err;
     }
     await invalidateKeys(queryClient, medicationDependentKeys);
     setSiteIntakeId(null);
diff --git a/src/components/medications/intake-edit-dialog.tsx b/src/components/medications/intake-edit-dialog.tsx
index 5e4b77b27..07c102539 100644
--- a/src/components/medications/intake-edit-dialog.tsx
+++ b/src/components/medications/intake-edit-dialog.tsx
@@ -39,6 +39,7 @@ import { Label } from "@/components/ui/label";
 import { Switch } from "@/components/ui/switch";
 import { useFormatters, useTranslations } from "@/lib/i18n/context";
 import { invalidateKeys, medicationDependentKeys } from "@/lib/query-keys";
+import { apiPut } from "@/lib/api/api-fetch";
 
 export interface IntakeEditDialogProps {
   medicationId: string;
@@ -132,18 +133,7 @@ function IntakeEditDialogBody({
       } else {
         body.takenAt = null;
       }
-      const res = await fetch(
-        `/api/medications/${medicationId}/intake/${event.id}`,
-        {
-          method: "PUT",
-          headers: { "Content-Type": "application/json" },
-          body: JSON.stringify(body),
-        },
-      );
-      if (!res.ok) {
-        toast.error(t("medications.detail.intake.edit.failed"));
-        return;
-      }
+      await apiPut(`/api/medications/${medicationId}/intake/${event.id}`, body);
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.intake.edit.savedToast"));
       onClose();
@@ -162,69 +152,80 @@ function IntakeEditDialogBody({
             {t("medications.detail.intake.edit.dialogTitle")}
           </DialogTitle>
         </DialogHeader>
-        <div className="space-y-3">
-          <div className="space-y-2">
-            <Label htmlFor="intake-edit-taken-at">
-              {t("medications.detail.intake.edit.takenAtLabel")}
-            </Label>
-            <Input
-              id="intake-edit-taken-at"
-              type="datetime-local"
-              value={takenAt}
-              max={toDateTimeLocal(new Date())}
-              onChange={(e) => setTakenAt(e.target.value)}
-              disabled={skipped}
-            />
-            {scheduledFor && (
-              <p
-                className="text-muted-foreground text-xs"
-                data-slot="intake-edit-scheduled-hint"
-              >
-                {t("medications.detail.intake.edit.scheduledForHint", {
-                  dateTime: fmt.dateTime(scheduledFor),
-                })}
-              </p>
-            )}
-            {/* Non-blocking: a 48h+ gap to the slot is almost always a
+        {/* v1.16.4 — a real form so Enter in the datetime field submits;
+            the buttons carry explicit types so cancel never submits. */}
+        <form
+          className="space-y-4"
+          onSubmit={(e) => {
+            e.preventDefault();
+            void save();
+          }}
+        >
+          <div className="space-y-3">
+            <div className="space-y-2">
+              <Label htmlFor="intake-edit-taken-at">
+                {t("medications.detail.intake.edit.takenAtLabel")}
+              </Label>
+              <Input
+                id="intake-edit-taken-at"
+                type="datetime-local"
+                value={takenAt}
+                max={toDateTimeLocal(new Date())}
+                onChange={(e) => setTakenAt(e.target.value)}
+                disabled={skipped}
+              />
+              {scheduledFor && (
+                <p
+                  className="text-muted-foreground text-xs"
+                  data-slot="intake-edit-scheduled-hint"
+                >
+                  {t("medications.detail.intake.edit.scheduledForHint", {
+                    dateTime: fmt.dateTime(scheduledFor),
+                  })}
+                </p>
+              )}
+              {/* Non-blocking: a 48h+ gap to the slot is almost always a
                 date typo, but a deliberate far edit stays saveable. */}
-            {showFarHint && (
-              <p
-                className="text-xs text-amber-600 dark:text-amber-400"
-                data-slot="intake-edit-far-hint"
-              >
-                {t("medications.detail.intake.edit.farFromScheduledWarning")}
-              </p>
-            )}
+              {showFarHint && (
+                <p
+                  className="text-xs text-amber-600 dark:text-amber-400"
+                  data-slot="intake-edit-far-hint"
+                >
+                  {t("medications.detail.intake.edit.farFromScheduledWarning")}
+                </p>
+              )}
+            </div>
+            <label
+              htmlFor="intake-edit-skipped"
+              className="flex items-center justify-between gap-3"
+            >
+              <span className="text-sm font-medium">
+                {t("medications.detail.intake.edit.skippedLabel")}
+              </span>
+              <Switch
+                id="intake-edit-skipped"
+                checked={skipped}
+                onCheckedChange={(checked) => setSkipped(checked)}
+              />
+            </label>
           </div>
-          <label
-            htmlFor="intake-edit-skipped"
-            className="flex items-center justify-between gap-3"
-          >
-            <span className="text-sm font-medium">
-              {t("medications.detail.intake.edit.skippedLabel")}
-            </span>
-            <Switch
-              id="intake-edit-skipped"
-              checked={skipped}
-              onCheckedChange={(checked) => setSkipped(checked)}
-            />
-          </label>
-        </div>
-        <DialogFooter>
-          <Button variant="outline" onClick={onClose} disabled={busy}>
-            {t("medications.detail.intake.edit.cancel")}
-          </Button>
-          <Button
-            onClick={() => void save()}
-            disabled={busy}
-            aria-busy={busy || undefined}
-          >
-            {busy && (
-              <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-            )}
-            {t("medications.detail.intake.edit.save")}
-          </Button>
-        </DialogFooter>
+          <DialogFooter>
+            <Button
+              type="button"
+              variant="outline"
+              onClick={onClose}
+              disabled={busy}
+            >
+              {t("medications.detail.intake.edit.cancel")}
+            </Button>
+            <Button type="submit" disabled={busy} aria-busy={busy || undefined}>
+              {busy && (
+                <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+              )}
+              {t("medications.detail.intake.edit.save")}
+            </Button>
+          </DialogFooter>
+        </form>
       </DialogContent>
     </Dialog>
   );
diff --git a/src/components/medications/intake-history-editable.tsx b/src/components/medications/intake-history-editable.tsx
index 78a440f10..0e162e955 100644
--- a/src/components/medications/intake-history-editable.tsx
+++ b/src/components/medications/intake-history-editable.tsx
@@ -41,6 +41,7 @@ import {
 } from "@/components/medications/intake-history-list-v2";
 import { useTranslations } from "@/lib/i18n/context";
 import { invalidateKeys, medicationDependentKeys } from "@/lib/query-keys";
+import { apiDelete, apiPost } from "@/lib/api/api-fetch";
 
 export interface IntakeHistoryEditableProps {
   medicationId: string;
@@ -90,18 +91,9 @@ export function IntakeHistoryEditable({
     setBulkBusy(true);
     const ids = Array.from(selected);
     try {
-      const res = await fetch(
-        `/api/medications/${medicationId}/intake/bulk-delete`,
-        {
-          method: "POST",
-          headers: { "Content-Type": "application/json" },
-          body: JSON.stringify({ eventIds: ids }),
-        },
-      );
-      if (!res.ok) {
-        toast.error(t("medications.detail.intake.bulkDelete.failed"));
-        return;
-      }
+      await apiPost(`/api/medications/${medicationId}/intake/bulk-delete`, {
+        eventIds: ids,
+      });
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.intake.bulkDelete.toast"));
       setBulkConfirmOpen(false);
@@ -118,13 +110,7 @@ export function IntakeHistoryEditable({
     setRowDeleteBusy(true);
     const id = pendingDeleteId;
     try {
-      const res = await fetch(`/api/medications/${medicationId}/intake/${id}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) {
-        toast.error(t("medications.detail.intake.deleteRow.failed"));
-        return;
-      }
+      await apiDelete(`/api/medications/${medicationId}/intake/${id}`);
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.intake.deleteRow.toast"));
       setPendingDeleteId(null);
diff --git a/src/components/medications/intake-history-list-v2.tsx b/src/components/medications/intake-history-list-v2.tsx
index a35dd9796..01a906a65 100644
--- a/src/components/medications/intake-history-list-v2.tsx
+++ b/src/components/medications/intake-history-list-v2.tsx
@@ -36,13 +36,14 @@ import {
   TableHeader,
   TableRow,
 } from "@/components/ui/table";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.36 W4a — Lite intake-history surface.
  *
  * The 886-LoC v1 was retired in v1.4.28 (commit 8c81af10) with the
  * note "no other consumer". The standalone medication-history page
- * lost its dose timeline as a side effect — Marc reported the page
+ * lost its dose timeline as a side effect — the maintainer reported the page
  * now shows only the heading for non-GLP-1 meds. This v2 restores a
  * read-only timeline for ALL medication kinds without the inline CRUD
  * the v1 carried (edit / delete still happen through the regular
@@ -187,11 +188,7 @@ export function IntakeHistoryListV2({
         offset: String(offset),
         status: STATUS_FILTER,
       });
-      const res = await fetch(
-        `/api/medications/${medicationId}/intake?${params.toString()}`,
-      );
-      if (!res.ok) throw new Error("Failed to load intake history");
-      return (await res.json()).data as IntakeListResponse;
+      return apiGet<IntakeListResponse>(`/api/medications/${medicationId}/intake?${params.toString()}`);
     },
     enabled: isAuthenticated,
   });
diff --git a/src/components/medications/intake-import-dialog.tsx b/src/components/medications/intake-import-dialog.tsx
index cfc0bb8a7..591bf85eb 100644
--- a/src/components/medications/intake-import-dialog.tsx
+++ b/src/components/medications/intake-import-dialog.tsx
@@ -38,6 +38,7 @@ import { Label } from "@/components/ui/label";
 import { Textarea } from "@/components/ui/textarea";
 import { useTranslations } from "@/lib/i18n/context";
 import { invalidateKeys, medicationDependentKeys } from "@/lib/query-keys";
+import { ApiError, apiPost } from "@/lib/api/api-fetch";
 
 export interface IntakeImportDialogProps {
   medicationId: string | null;
@@ -107,18 +108,12 @@ export function IntakeImportDialog({
         else throw new Error(t("medications.importNoArray"));
       }
 
-      const res = await fetch(
-        `/api/medications/${medicationId}/intake/import`,
-        {
-          method: "POST",
-          headers: { "Content-Type": "application/json" },
-          body: JSON.stringify(data),
-        },
-      );
-
-      const json = await res.json();
-      if (res.ok) {
-        const d = json.data;
+      try {
+        const d = await apiPost<{
+          imported: number;
+          skippedDuplicates: number;
+          skippedInvalid: number;
+        }>(`/api/medications/${medicationId}/intake/import`, data);
         setResult(
           t("medications.importResult", { imported: d.imported }) +
             (d.skippedDuplicates > 0
@@ -130,8 +125,9 @@ export function IntakeImportDialog({
         );
         setResultType("success");
         void invalidateKeys(queryClient, medicationDependentKeys);
-      } else {
-        setResult(json.error || t("medications.importFailed"));
+      } catch (err) {
+        if (!(err instanceof ApiError)) throw err;
+        setResult(err.message || t("medications.importFailed"));
         setResultType("error");
       }
     } catch (err) {
diff --git a/src/components/medications/log-intake-dialog.tsx b/src/components/medications/log-intake-dialog.tsx
index e7d4cebe3..82916a4e2 100644
--- a/src/components/medications/log-intake-dialog.tsx
+++ b/src/components/medications/log-intake-dialog.tsx
@@ -215,6 +215,16 @@ export function LogIntakeDialog({
           </DialogDescription>
         </DialogHeader>
 
+        {/* v1.16.4 — a real form so Enter in the dose / datetime fields
+            submits; mirrors the intake-edit and dose-history-add dialogs. */}
+        <form
+          onSubmit={(e) => {
+            e.preventDefault();
+            if (busy || medications.length === 0 || !medicationId) return;
+            void submit();
+          }}
+          className="space-y-4"
+        >
         {medications.length === 0 ? (
           <p className="text-muted-foreground py-4 text-sm">
             {t("medications.logIntake.noMedications")}
@@ -318,6 +328,7 @@ export function LogIntakeDialog({
 
         <DialogFooter>
           <Button
+            type="button"
             variant="outline"
             onClick={() => onOpenChange(false)}
             disabled={busy}
@@ -325,7 +336,7 @@ export function LogIntakeDialog({
             {t("medications.logIntake.cancel")}
           </Button>
           <Button
-            onClick={() => void submit()}
+            type="submit"
             disabled={busy || medications.length === 0 || !medicationId}
             aria-busy={busy || undefined}
           >
@@ -335,6 +346,7 @@ export function LogIntakeDialog({
             {t("medications.logIntake.submit")}
           </Button>
         </DialogFooter>
+        </form>
       </DialogContent>
     </Dialog>
   );
diff --git a/src/components/medications/medication-card.tsx b/src/components/medications/medication-card.tsx
index cd9f8f339..611d6728d 100644
--- a/src/components/medications/medication-card.tsx
+++ b/src/components/medications/medication-card.tsx
@@ -22,6 +22,7 @@ import {
   medicationDependentKeys,
   queryKeys,
 } from "@/lib/query-keys";
+import { apiGet, apiPost } from "@/lib/api/api-fetch";
 import { LogInjectionSiteDialog } from "@/components/medications/log-injection-site-dialog";
 import { useGlobalExcludedInjectionSites } from "@/lib/medications/use-injection-site-prefs";
 import type { InjectionSiteKey } from "@/lib/medications/injection-sites";
@@ -149,10 +150,13 @@ export function MedicationCard({
   const { data: compliance } = useQuery({
     queryKey: queryKeys.medicationCompliance(medication.id),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medication.id}/compliance`);
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as ComplianceData;
+      try {
+        return await apiGet<ComplianceData>(
+          `/api/medications/${medication.id}/compliance`,
+        );
+      } catch {
+        return null;
+      }
     },
     // v1.15.20 — the card renders two percentage rows that move on a
     // dose action (which invalidates this key through
@@ -167,10 +171,13 @@ export function MedicationCard({
   const { data: thresholds } = useQuery({
     queryKey: queryKeys.settingsReminderThresholds(),
     queryFn: async () => {
-      const res = await fetch("/api/settings/reminder-thresholds");
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as { lateMinutes: number; missedMinutes: number };
+      try {
+        return await apiGet<{ lateMinutes: number; missedMinutes: number }>(
+          "/api/settings/reminder-thresholds",
+        );
+      } catch {
+        return null;
+      }
     },
     staleTime: 5 * 60 * 1000,
   });
@@ -186,14 +193,15 @@ export function MedicationCard({
     // v1.11.5 — keep the dialog open until the PATCH resolves. On failure
     // surface a toast and re-throw so the dialog stays mounted with the
     // chosen site instead of dismissing as though the site had been saved.
-    const res = await fetch("/api/medications/intake", {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ intakeId, status: "taken", injectionSite: site }),
-    });
-    if (!res.ok) {
+    try {
+      await apiPost("/api/medications/intake", {
+        intakeId,
+        status: "taken",
+        injectionSite: site,
+      });
+    } catch (err) {
       toast.error(t("medications.logInjectionSiteSaveFailed"));
-      throw new Error("injection-site PATCH failed");
+      throw err;
     }
     await invalidateKeys(queryClient, medicationDependentKeys);
     setSiteIntakeId(null);
diff --git a/src/components/medications/scheduling/DoseWindowEditor.tsx b/src/components/medications/scheduling/DoseWindowEditor.tsx
index b3553d379..fff33b26a 100644
--- a/src/components/medications/scheduling/DoseWindowEditor.tsx
+++ b/src/components/medications/scheduling/DoseWindowEditor.tsx
@@ -1,7 +1,7 @@
 "use client";
 
 /**
- * v1.15.18 — per-dose configurable on-time WINDOW editor (Marc's headline
+ * v1.15.18 — per-dose configurable on-time WINDOW editor (the maintainer's headline
  * lever). Shared verbatim by the Zeitplan tab (everyday inline edit) and
  * the wizard's Step 7 (structural create / edit) so the window semantics
  * are identical wherever a dose time is set.
diff --git a/src/components/medications/scheduling/ScheduleTimesEditor.tsx b/src/components/medications/scheduling/ScheduleTimesEditor.tsx
index c01219947..48b5fcdb2 100644
--- a/src/components/medications/scheduling/ScheduleTimesEditor.tsx
+++ b/src/components/medications/scheduling/ScheduleTimesEditor.tsx
@@ -32,6 +32,7 @@ import {
 import { useTranslations } from "@/lib/i18n/context";
 import { parseScheduleRecurrence } from "@/lib/medication-schedule";
 import { invalidateKeys, medicationDependentKeys } from "@/lib/query-keys";
+import { apiPut } from "@/lib/api/api-fetch";
 
 /** The schedule fields the inline editor reads + round-trips on save. */
 export interface EditableSchedule {
@@ -159,15 +160,7 @@ export function ScheduleTimesEditor({
         }),
       };
 
-      const res = await fetch(`/api/medications/${medicationId}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      if (!res.ok) {
-        toast.error(t("medications.detail.zeitplan.failed"));
-        return;
-      }
+      await apiPut(`/api/medications/${medicationId}`, body);
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.zeitplan.saved"));
     } catch {
diff --git a/src/components/medications/scheduling/dose-window.ts b/src/components/medications/scheduling/dose-window.ts
index e260a1bb3..7e8b12367 100644
--- a/src/components/medications/scheduling/dose-window.ts
+++ b/src/components/medications/scheduling/dose-window.ts
@@ -1,5 +1,5 @@
 /**
- * v1.15.18 — per-dose configurable on-time WINDOW helpers (Marc's
+ * v1.15.18 — per-dose configurable on-time WINDOW helpers (the maintainer's
  * headline lever).
  *
  * A dose time can be expressed two ways:
diff --git a/src/components/medications/sections/api-tokens-row.tsx b/src/components/medications/sections/api-tokens-row.tsx
index baf235b29..6d7b5f8e2 100644
--- a/src/components/medications/sections/api-tokens-row.tsx
+++ b/src/components/medications/sections/api-tokens-row.tsx
@@ -36,6 +36,7 @@ import {
   medicationDependentKeys,
   queryKeys,
 } from "@/lib/query-keys";
+import { ApiError, apiGet, apiPut } from "@/lib/api/api-fetch";
 
 export interface ApiTokensRowProps {
   medicationId: string;
@@ -74,12 +75,13 @@ export function ApiTokensRow({
   const { data: status } = useQuery<ApiEndpointStatus>({
     queryKey,
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medicationId}/api-endpoint`);
-      if (!res.ok) throw new Error("status_failed");
-      const json = await res.json();
+      const data = await apiGet<{
+        enabled?: boolean;
+        activeTokenCount?: number;
+      }>(`/api/medications/${medicationId}/api-endpoint`);
       return {
-        enabled: json.data.enabled === true,
-        activeTokenCount: json.data.activeTokenCount ?? 0,
+        enabled: data.enabled === true,
+        activeTokenCount: data.activeTokenCount ?? 0,
       };
     },
     staleTime: 0,
@@ -149,21 +151,16 @@ export function ApiTokensRow({
     if (busy) return;
     setBusy(true);
     try {
-      const res = await fetch(`/api/medications/${medicationId}/api-endpoint`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ enabled: true }),
-      });
-      const json = await res.json();
-      if (!res.ok) {
-        toast.error(json.error ?? t("medications.detail.api.mintFailed"));
-        return;
-      }
-      if (json.data.token) {
-        setMintedToken(json.data.token);
+      const data = await apiPut<{
+        token?: string;
+        enabled?: boolean;
+        activeTokenCount?: number;
+      }>(`/api/medications/${medicationId}/api-endpoint`, { enabled: true });
+      if (data.token) {
+        setMintedToken(data.token);
         // Auto-copy on mint so the user has it without an extra tap.
         try {
-          await navigator.clipboard.writeText(json.data.token);
+          await navigator.clipboard.writeText(data.token);
         } catch {
           // Clipboard rejection is silent — the value is still visible
           // in the read-only one-shot panel below.
@@ -174,14 +171,18 @@ export function ApiTokensRow({
         queryKeys.tokens(),
       ]);
       queryClient.setQueryData<ApiEndpointStatus>(queryKey, {
-        enabled: json.data.enabled === true,
+        enabled: data.enabled === true,
         activeTokenCount:
-          typeof json.data.activeTokenCount === "number"
-            ? json.data.activeTokenCount
+          typeof data.activeTokenCount === "number"
+            ? data.activeTokenCount
             : (status?.activeTokenCount ?? 0) + 1,
       });
-    } catch {
-      toast.error(t("medications.detail.api.mintFailed"));
+    } catch (err) {
+      toast.error(
+        err instanceof ApiError && err.message
+          ? err.message
+          : t("medications.detail.api.mintFailed"),
+      );
     } finally {
       setBusy(false);
     }
diff --git a/src/components/medications/sections/destructive-zone-section.tsx b/src/components/medications/sections/destructive-zone-section.tsx
index c686e9f04..8a3765451 100644
--- a/src/components/medications/sections/destructive-zone-section.tsx
+++ b/src/components/medications/sections/destructive-zone-section.tsx
@@ -51,6 +51,7 @@ import {
   medicationDependentKeys,
   queryKeys,
 } from "@/lib/query-keys";
+import { apiDelete, apiPut } from "@/lib/api/api-fetch";
 
 const PAUSE_SWITCH_ID = "medication-detail-pause-switch";
 const PAUSE_TITLE_ID = "medication-detail-pause-title";
@@ -87,16 +88,7 @@ export function LifecycleManageBody({
     try {
       // v1.5.5 C-E3-2 — body carries `{ active }` only; server derives
       // pausedAt. No client-side pausedAt literal.
-      const res = await fetch(`/api/medications/${medicationId}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ active: !pauseNext }),
-      });
-      if (!res.ok) {
-        setPaused(previous);
-        toast.error(t("medications.detail.zone.pause.failed"));
-        return;
-      }
+      await apiPut(`/api/medications/${medicationId}`, { active: !pauseNext });
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(
         pauseNext
@@ -117,15 +109,7 @@ export function LifecycleManageBody({
     setTier2Busy(true);
     try {
       const today = new Date().toISOString();
-      const res = await fetch(`/api/medications/${medicationId}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ endsOn: today }),
-      });
-      if (!res.ok) {
-        toast.error(t("medications.detail.zone.end.failed"));
-        return;
-      }
+      await apiPut(`/api/medications/${medicationId}`, { endsOn: today });
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.zone.end.toast"));
       setEndDialogOpen(false);
@@ -261,13 +245,7 @@ export function DangerZoneBody({
     if (tier3aBusy) return;
     setTier3aBusy(true);
     try {
-      const res = await fetch(`/api/medications/${medicationId}/intake/purge`, {
-        method: "DELETE",
-      });
-      if (!res.ok) {
-        toast.error(t("medications.detail.zone.purge.failed"));
-        return;
-      }
+      await apiDelete(`/api/medications/${medicationId}/intake/purge`);
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.zone.purge.toast"));
       setPurgeDialogOpen(false);
@@ -283,14 +261,7 @@ export function DangerZoneBody({
     if (tier3bBusy) return;
     setTier3bBusy(true);
     try {
-      const res = await fetch(`/api/medications/${medicationId}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) {
-        toast.error(t("medications.detail.zone.delete.failed"));
-        setTier3bBusy(false);
-        return;
-      }
+      await apiDelete(`/api/medications/${medicationId}`);
       // Drop the deleted medication's own detail query before the
       // prefix-invalidate below. `medicationDependentKeys` carries
       // `["medications"]`, which covers the active `["medications", id]`
diff --git a/src/components/medications/sections/inventory-section.tsx b/src/components/medications/sections/inventory-section.tsx
index 3e7e1c02f..195763ce1 100644
--- a/src/components/medications/sections/inventory-section.tsx
+++ b/src/components/medications/sections/inventory-section.tsx
@@ -42,6 +42,7 @@ import { Input } from "@/components/ui/input";
 import { SettingsGroup } from "@/components/medications/settings-group";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet, apiPatch, apiPost } from "@/lib/api/api-fetch";
 
 type InventoryState = "ACTIVE" | "IN_USE" | "EXPIRED" | "USED_UP";
 
@@ -79,9 +80,7 @@ export function InventorySection({
   const { data, isLoading } = useQuery<InventoryResponse>({
     queryKey: queryKeys.medicationInventory(medicationId),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medicationId}/inventory`);
-      if (!res.ok) throw new Error("inventory_failed");
-      return (await res.json()).data as InventoryResponse;
+      return apiGet<InventoryResponse>(`/api/medications/${medicationId}/inventory`);
     },
     staleTime: 30_000,
   });
@@ -242,20 +241,12 @@ function AddInventoryDialog({
     if (!quantityValid || busy) return;
     setBusy(true);
     try {
-      const res = await fetch(`/api/medications/${medicationId}/inventory`, {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          dosesTotal: parsed,
-          printedExpiry: expiry
-            ? new Date(`${expiry}T00:00:00`).toISOString()
-            : null,
-        }),
+      await apiPost(`/api/medications/${medicationId}/inventory`, {
+        dosesTotal: parsed,
+        printedExpiry: expiry
+          ? new Date(`${expiry}T00:00:00`).toISOString()
+          : null,
       });
-      if (!res.ok) {
-        toast.error(t("medications.detail.bestand.addFailed"));
-        return;
-      }
       await queryClient.invalidateQueries({
         queryKey: queryKeys.medicationInventory(medicationId),
       });
@@ -373,18 +364,9 @@ function AdjustInventoryDialog({
     if (!valid || busy) return;
     setBusy(true);
     try {
-      const res = await fetch(
-        `/api/medications/${medicationId}/inventory/${item.id}`,
-        {
-          method: "PATCH",
-          headers: { "Content-Type": "application/json" },
-          body: JSON.stringify({ dosesRemaining: parsed }),
-        },
-      );
-      if (!res.ok) {
-        toast.error(t("medications.detail.bestand.adjustFailed"));
-        return;
-      }
+      await apiPatch(`/api/medications/${medicationId}/inventory/${item.id}`, {
+        dosesRemaining: parsed,
+      });
       await queryClient.invalidateQueries({
         queryKey: queryKeys.medicationInventory(medicationId),
       });
diff --git a/src/components/medications/sections/notifications-section.tsx b/src/components/medications/sections/notifications-section.tsx
index 07d2eccff..f5d2e2480 100644
--- a/src/components/medications/sections/notifications-section.tsx
+++ b/src/components/medications/sections/notifications-section.tsx
@@ -34,6 +34,7 @@ import {
   medicationDependentKeys,
   queryKeys,
 } from "@/lib/query-keys";
+import { apiGet, apiPut } from "@/lib/api/api-fetch";
 
 export interface NotificationsSectionProps {
   medicationId: string;
@@ -103,9 +104,7 @@ export function NotificationsBody({
   const { data: status } = useQuery<NotificationStatusResponse>({
     queryKey: queryKeys.notificationsStatus(),
     queryFn: async () => {
-      const res = await fetch("/api/notifications/status");
-      if (!res.ok) throw new Error("status_failed");
-      return (await res.json()).data as NotificationStatusResponse;
+      return apiGet<NotificationStatusResponse>("/api/notifications/status");
     },
     enabled: isAuthenticated,
     staleTime: 60_000,
@@ -114,9 +113,7 @@ export function NotificationsBody({
   const { data: prefs } = useQuery<UserPrefsResponse>({
     queryKey: queryKeys.authMe(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/me");
-      if (!res.ok) throw new Error("auth_failed");
-      return (await res.json()).data as UserPrefsResponse;
+      return apiGet<UserPrefsResponse>("/api/auth/me");
     },
     enabled: isAuthenticated,
     staleTime: 60_000,
@@ -131,16 +128,9 @@ export function NotificationsBody({
     const previous = localEnabled;
     setLocalEnabled(next);
     try {
-      const res = await fetch(`/api/medications/${medicationId}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ notificationsEnabled: next }),
+      await apiPut(`/api/medications/${medicationId}`, {
+        notificationsEnabled: next,
       });
-      if (!res.ok) {
-        setLocalEnabled(previous);
-        toast.error(t("medications.detail.notifications.toggleFailed"));
-        return;
-      }
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(
         next
diff --git a/src/components/medications/sections/phase-config-sheet.tsx b/src/components/medications/sections/phase-config-sheet.tsx
index b88786888..b40933e85 100644
--- a/src/components/medications/sections/phase-config-sheet.tsx
+++ b/src/components/medications/sections/phase-config-sheet.tsx
@@ -47,6 +47,7 @@ import {
   medicationDependentKeys,
   queryKeys,
 } from "@/lib/query-keys";
+import { ApiError, apiGet, apiPut } from "@/lib/api/api-fetch";
 
 type PhaseMode = "MINUTES" | "PERCENT";
 
@@ -138,9 +139,11 @@ export function PhaseConfigSheet({
   const { data, isLoading, isError } = useQuery({
     queryKey: queryKeys.medicationPhaseConfig(medicationId),
     queryFn: async () => {
-      const res = await fetch(`/api/medications/${medicationId}/phase-config`);
-      if (!res.ok) throw new Error("phase_config_failed");
-      return fromApi((await res.json()).data as PhaseConfigApiPayload);
+      return fromApi(
+        await apiGet<PhaseConfigApiPayload>(
+          `/api/medications/${medicationId}/phase-config`,
+        ),
+      );
     },
     enabled: open,
     staleTime: 0,
@@ -216,27 +219,19 @@ function PhaseConfigForm({
   async function save() {
     setSaving(true);
     try {
-      const res = await fetch(`/api/medications/${medicationId}/phase-config`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(toApi(cfg)),
-      });
-      if (!res.ok) {
-        const json = await res.json().catch(() => ({}));
-        toast.error(
-          (json as { error?: string }).error ??
-            t("medications.detail.phases.saveFailed"),
-        );
-        return;
-      }
+      await apiPut(`/api/medications/${medicationId}/phase-config`, toApi(cfg));
       await invalidateKeys(queryClient, [
         ...medicationDependentKeys,
         queryKeys.medicationPhaseConfig(medicationId),
       ]);
       toast.success(t("medications.phaseSaved"));
       onClose();
-    } catch {
-      toast.error(t("medications.detail.phases.saveFailed"));
+    } catch (err) {
+      toast.error(
+        err instanceof ApiError && err.message
+          ? err.message
+          : t("medications.detail.phases.saveFailed"),
+      );
     } finally {
       setSaving(false);
     }
diff --git a/src/components/medications/sections/settings-section.tsx b/src/components/medications/sections/settings-section.tsx
index c9cbaa91e..cea70218a 100644
--- a/src/components/medications/sections/settings-section.tsx
+++ b/src/components/medications/sections/settings-section.tsx
@@ -29,6 +29,7 @@ import { PhaseConfigSheet } from "@/components/medications/sections/phase-config
 import { useTranslations } from "@/lib/i18n/context";
 import { parseScheduleRecurrence } from "@/lib/medication-schedule";
 import { invalidateKeys, medicationDependentKeys } from "@/lib/query-keys";
+import { apiPut } from "@/lib/api/api-fetch";
 import type { DoseWindowEntry } from "@/components/medications/scheduling/dose-window";
 
 /** The schedule fields the grace save round-trips on a wholesale PUT. */
@@ -122,15 +123,7 @@ export function GraceRow({
             }),
           }
         : { reminderGraceMinutes: graceValue };
-      const res = await fetch(`/api/medications/${medicationId}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      if (!res.ok) {
-        toast.error(t("medications.detail.settings.grace.failed"));
-        return;
-      }
+      await apiPut(`/api/medications/${medicationId}`, body);
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.settings.grace.saved"));
     } catch {
@@ -210,18 +203,10 @@ export function DrugCodingRow({
     try {
       // Empty input clears the column (null); a non-empty value is sent
       // verbatim for the server to validate (422 on a malformed code).
-      const res = await fetch(`/api/medications/${medicationId}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          atcCode: atcValue.trim() === "" ? null : atcValue.trim(),
-          rxNormCode: rxValue.trim() === "" ? null : rxValue.trim(),
-        }),
+      await apiPut(`/api/medications/${medicationId}`, {
+        atcCode: atcValue.trim() === "" ? null : atcValue.trim(),
+        rxNormCode: rxValue.trim() === "" ? null : rxValue.trim(),
       });
-      if (!res.ok) {
-        toast.error(t("medications.detail.settings.codes.failed"));
-        return;
-      }
       await invalidateKeys(queryClient, medicationDependentKeys);
       toast.success(t("medications.detail.settings.codes.saved"));
     } catch {
diff --git a/src/components/medications/use-medication-intake.ts b/src/components/medications/use-medication-intake.ts
index 807f1c5fb..96055fdab 100644
--- a/src/components/medications/use-medication-intake.ts
+++ b/src/components/medications/use-medication-intake.ts
@@ -6,6 +6,7 @@ import { toast } from "sonner";
 
 import { useTranslations } from "@/lib/i18n/context";
 import { invalidateKeys, medicationDependentKeys } from "@/lib/query-keys";
+import { apiDelete, apiPost } from "@/lib/api/api-fetch";
 
 type Translator = (
   key: string,
@@ -97,37 +98,26 @@ export async function runRecordIntake(deps: {
 
   setIntakeLoading(skipped ? "skip" : "take");
   try {
-    const res = await fetch(`/api/medications/${medication.id}/intake`, {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      // The route's Zod schema accepts an ISO `scheduledFor`; the server
-      // snaps it to the canonical slot. Only send it when the card
-      // identified the displayed dose's slot — otherwise omit so the
-      // PRN / unscheduled now-snap path is preserved.
-      body: JSON.stringify(
-        scheduledFor
-          ? { skipped, scheduledFor: scheduledFor.toISOString() }
-          : { skipped },
-      ),
-    });
+    // The route's Zod schema accepts an ISO `scheduledFor`; the server
+    // snaps it to the canonical slot. Only send it when the card
+    // identified the displayed dose's slot — otherwise omit so the
+    // PRN / unscheduled now-snap path is preserved.
+    //
     // v1.11.3 C1 — a failed POST used to clear the spinner silently, so the
-    // user believed the dose was logged when it was not. Surface the failure
-    // and never show the success confirmation in that case. (The GLP-1 card
-    // missed this port until v1.12.2 lifted the logic here.)
-    if (!res.ok) {
-      toast.error(t("medications.intakeToastFailed", { name: medication.name }));
-      return;
-    }
+    // user believed the dose was logged when it was not. apiPost throws on
+    // non-OK, so the catch below surfaces the failure and the success
+    // confirmation never shows in that case.
+    //
     // The POST returns the created event (`apiSuccess(event, 201)`); its id
     // drives both the Undo affordance and the card's post-success hook
     // (the optional injection-site prompt).
-    let eventId: string | undefined;
-    try {
-      const json = await res.json();
-      eventId = json?.data?.id as string | undefined;
-    } catch {
-      /* dose recorded; the body is best-effort for the id */
-    }
+    const created = await apiPost<{ id?: string } | undefined>(
+      `/api/medications/${medication.id}/intake`,
+      scheduledFor
+        ? { skipped, scheduledFor: scheduledFor.toISOString() }
+        : { skipped },
+    );
+    const eventId: string | undefined = created?.id;
     // v1.11.3 C2 — the success toast carries an Undo action so a misclicked
     // take / skip no longer needs a history dive to correct.
     toast.success(
@@ -197,15 +187,7 @@ export async function runLogIntake(deps: {
     if (!skipped) body.takenAt = takenAt;
     if (scheduledFor) body.scheduledFor = scheduledFor;
     if (!skipped && doseTaken) body.doseTaken = doseTaken;
-    const res = await fetch(`/api/medications/${medication.id}/intake`, {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify(body),
-    });
-    if (!res.ok) {
-      toast.error(t("medications.intakeToastFailed", { name: medication.name }));
-      return false;
-    }
+    await apiPost(`/api/medications/${medication.id}/intake`, body);
     await invalidateKeys(queryClient, medicationDependentKeys);
     toast.success(
       t(
@@ -234,14 +216,7 @@ export async function runUndoIntake(deps: {
 }): Promise<void> {
   const { medication, eventId, t, queryClient } = deps;
   try {
-    const res = await fetch(
-      `/api/medications/${medication.id}/intake/${eventId}`,
-      { method: "DELETE" },
-    );
-    if (!res.ok) {
-      toast.error(t("medications.intakeUndoFailed"));
-      return;
-    }
+    await apiDelete(`/api/medications/${medication.id}/intake/${eventId}`);
     await invalidateKeys(queryClient, medicationDependentKeys);
     toast.success(t("medications.intakeUndone"));
   } catch {
diff --git a/src/components/medications/wizard/steps/Step2Class.tsx b/src/components/medications/wizard/steps/Step2Class.tsx
index 52e2644b7..b33f4f959 100644
--- a/src/components/medications/wizard/steps/Step2Class.tsx
+++ b/src/components/medications/wizard/steps/Step2Class.tsx
@@ -24,7 +24,7 @@ import {
 } from "../wizard-payload";
 import type { StepProps } from "./Step1Name";
 
-// Each row's Lucide glyph. Marc-confirmed assignment in D-1 §3 Step 2.
+// Each row's Lucide glyph. maintainer-confirmed assignment in D-1 §3 Step 2.
 const ROW_ICONS: Record<
   WizardTreatmentRow,
   ComponentType<LucideProps>
diff --git a/src/components/medications/wizard/steps/Step8Summary.tsx b/src/components/medications/wizard/steps/Step8Summary.tsx
index 29f9c2230..a0b6355bc 100644
--- a/src/components/medications/wizard/steps/Step8Summary.tsx
+++ b/src/components/medications/wizard/steps/Step8Summary.tsx
@@ -9,6 +9,7 @@ import { Label } from "@/components/ui/label";
 import { Switch } from "@/components/ui/switch";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet } from "@/lib/api/api-fetch";
 
 import {
   type MedicationPayload,
@@ -67,10 +68,10 @@ export function Step8Summary({
   const { data: notificationChannels } = useQuery({
     queryKey: queryKeys.notificationsStatus(),
     queryFn: async () => {
-      const res = await fetch("/api/notifications/status");
-      if (!res.ok) throw new Error("Failed");
-      return ((await res.json()).data as { channels: Array<{ enabled: boolean }> })
-        .channels;
+      const data = await apiGet<{ channels: Array<{ enabled: boolean }> }>(
+        "/api/notifications/status",
+      );
+      return data.channels;
     },
     enabled: payload.notificationsEnabled,
     staleTime: 60_000,
diff --git a/src/components/medications/wizard/wizard-payload.ts b/src/components/medications/wizard/wizard-payload.ts
index 7a7cffa44..956e3430f 100644
--- a/src/components/medications/wizard/wizard-payload.ts
+++ b/src/components/medications/wizard/wizard-payload.ts
@@ -91,7 +91,7 @@ export type WizardTreatmentRow =
   | "other";
 
 /**
- * The ten taxonomy rows in their visible order. Marc-confirmed (D-1
+ * The ten taxonomy rows in their visible order. maintainer-confirmed (D-1
  * §3 Step 2): Blutdruck · Diabetes · Hormone · GLP-1-Injektion ·
  * Schmerz · Allergie · Vitamine · Nahrungsergänzung · Antibiotikum ·
  * Sonstiges.
diff --git a/src/components/monitoring/bootstrap.tsx b/src/components/monitoring/bootstrap.tsx
index b58c52142..0598dcff5 100644
--- a/src/components/monitoring/bootstrap.tsx
+++ b/src/components/monitoring/bootstrap.tsx
@@ -3,6 +3,7 @@
 import { useEffect, useState } from "react";
 import { UmamiScript } from "@/components/monitoring/umami-script";
 import { GlitchtipReporter } from "@/components/monitoring/glitchtip-reporter";
+import { apiGet } from "@/lib/api/api-fetch";
 
 interface MonitoringSettings {
   umamiEnabled: boolean;
@@ -16,11 +17,12 @@ export function MonitoringBootstrap() {
   useEffect(() => {
     let active = true;
 
-    fetch("/api/monitoring/settings", { cache: "no-store" })
-      .then((response) => (response.ok ? response.json() : null))
-      .then((json) => {
-        if (!active || !json?.data) return;
-        setSettings(json.data as MonitoringSettings);
+    apiGet<MonitoringSettings | undefined>("/api/monitoring/settings", {
+      cache: "no-store",
+    })
+      .then((data) => {
+        if (!active || !data) return;
+        setSettings(data);
       })
       .catch(() => {
         if (!active) return;
diff --git a/src/components/monitoring/glitchtip-reporter.tsx b/src/components/monitoring/glitchtip-reporter.tsx
index a544bfbdc..a70ef2e99 100644
--- a/src/components/monitoring/glitchtip-reporter.tsx
+++ b/src/components/monitoring/glitchtip-reporter.tsx
@@ -2,6 +2,8 @@
 
 import { useEffect } from "react";
 
+import { apiPost } from "@/lib/api/api-fetch";
+
 interface GlitchtipReporterProps {
   enabled: boolean;
 }
@@ -12,16 +14,15 @@ function sendClientError(payload: {
   level?: "error" | "warning" | "info";
   type?: string;
 }) {
-  fetch("/api/monitoring/glitchtip", {
-    method: "POST",
-    headers: { "Content-Type": "application/json" },
-    body: JSON.stringify({
+  apiPost(
+    "/api/monitoring/glitchtip",
+    {
       ...payload,
       url: window.location.href,
       userAgent: navigator.userAgent,
-    }),
-    keepalive: true,
-  }).catch(() => {});
+    },
+    { keepalive: true },
+  ).catch(() => {});
 }
 
 export function GlitchtipReporter({ enabled }: GlitchtipReporterProps) {
diff --git a/src/components/mood/__tests__/mood-list-filter-select.test.tsx b/src/components/mood/__tests__/mood-list-filter-select.test.tsx
index 64438ff32..ef0e2b8c9 100644
--- a/src/components/mood/__tests__/mood-list-filter-select.test.tsx
+++ b/src/components/mood/__tests__/mood-list-filter-select.test.tsx
@@ -54,7 +54,7 @@ vi.mock("@tanstack/react-query", () => ({
 
 vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
-    user: { id: "u1", username: "marc", role: "USER" },
+    user: { id: "u1", username: "testuser", role: "USER" },
     isAuthenticated: true,
     isLoading: false,
   }),
diff --git a/src/components/mood/mood-form.tsx b/src/components/mood/mood-form.tsx
index 6477be53e..3373b754d 100644
--- a/src/components/mood/mood-form.tsx
+++ b/src/components/mood/mood-form.tsx
@@ -29,6 +29,7 @@ import { toast } from "sonner";
 import { useTranslations } from "@/lib/i18n/context";
 import { useRovingRadioGroup } from "@/hooks/use-roving-radio-group";
 import { invalidateKeys, moodDependentKeys } from "@/lib/query-keys";
+import { ApiError, apiPost } from "@/lib/api/api-fetch";
 import { MoodTagPicker, type RatedFactor } from "./mood-tag-picker";
 import { moodFaceIcon } from "./mood-tag-icons";
 
@@ -182,33 +183,26 @@ export function MoodForm({ onSuccess, onCancel, footerSlot }: MoodFormProps) {
 
       const trimmedNote = note.trim();
 
-      const res = await fetch("/api/mood-entries", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          mood,
-          tags: tags.length > 0 ? tags : undefined,
-          tagKeys: tagKeys.length > 0 ? tagKeys : undefined,
-          // v1.12.0 — rated factors as a parallel [{key,rating}] array.
-          ratedFactors: ratedFactors.length > 0 ? ratedFactors : undefined,
-          note: trimmedNote.length > 0 ? trimmedNote : undefined,
-          moodLoggedAt: timestamp,
-        }),
+      await apiPost("/api/mood-entries", {
+        mood,
+        tags: tags.length > 0 ? tags : undefined,
+        tagKeys: tagKeys.length > 0 ? tagKeys : undefined,
+        // v1.12.0 — rated factors as a parallel [{key,rating}] array.
+        ratedFactors: ratedFactors.length > 0 ? ratedFactors : undefined,
+        note: trimmedNote.length > 0 ? trimmedNote : undefined,
+        moodLoggedAt: timestamp,
       });
 
-      const json = await res.json();
-      if (!res.ok) {
-        setError(json.error);
-        setLoading(false);
-        return;
-      }
-
       resetForm();
       await invalidateKeys(queryClient, moodDependentKeys);
       toast.success(t("common.saved"));
       onSuccess?.();
-    } catch {
-      setError(t("mood.saveError"));
+    } catch (err) {
+      setError(
+        err instanceof ApiError && err.message
+          ? err.message
+          : t("mood.saveError"),
+      );
     } finally {
       setLoading(false);
     }
diff --git a/src/components/mood/mood-list.tsx b/src/components/mood/mood-list.tsx
index 57b87fbfe..9967d0105 100644
--- a/src/components/mood/mood-list.tsx
+++ b/src/components/mood/mood-list.tsx
@@ -55,7 +55,7 @@ import {
   ChevronRight,
   MoreHorizontal,
 } from "lucide-react";
-import { useId, useState } from "react";
+import { useCallback, useId, useState } from "react";
 import { createPortal } from "react-dom";
 import { toast } from "sonner";
 import { formatDateTime } from "@/lib/format";
@@ -76,6 +76,7 @@ import {
 } from "@/components/data-list";
 import { useRovingRadioGroup } from "@/hooks/use-roving-radio-group";
 import { MoodTagPicker } from "./mood-tag-picker";
+import { apiDelete, apiGet, apiPost, apiPut } from "@/lib/api/api-fetch";
 
 // Re-export the score map under the legacy local name to keep the
 // rest of this file unchanged. v1.4.27 B6 / BL-P6-11 — the single
@@ -235,26 +236,43 @@ export function MoodList({ onAddFirst }: MoodListProps = {}) {
       params.set("offset", String((page - 1) * PAGE_SIZE));
       params.set("sortBy", sortBy);
       params.set("sortDir", sortDir);
-      const res = await fetch(`/api/mood-entries?${params}`);
-      if (!res.ok) throw new Error("Failed to fetch");
-      const json = await res.json();
-      return json.data as {
+      return apiGet<{
         entries: MoodEntry[];
         meta: { total: number };
-      };
+      }>(`/api/mood-entries?${params}`);
     },
     enabled: isAuthenticated,
   });
 
+  // v1.16.4 — deletes are soft (tombstones), so the success toast can
+  // carry a real Undo: it POSTs the ids to `/api/mood-entries/restore`,
+  // which clears `deletedAt` and re-fires the same dependent-key bundle.
+  // Mirrors the measurements list and the intake-Undo pattern.
+  const restoreEntries = useCallback(
+    async (ids: string[]) => {
+      try {
+        await apiPost("/api/mood-entries/restore", { ids });
+        await invalidateKeys(queryClient, moodDependentKeys);
+        toast.success(t("mood.restoredToast"));
+      } catch {
+        toast.error(t("mood.restoreError"));
+      }
+    },
+    [queryClient, t],
+  );
+
   const deleteMutation = useMutation({
     mutationFn: async (id: string) => {
-      const res = await fetch(`/api/mood-entries/${id}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) throw new Error("Delete failed");
+      await apiDelete(`/api/mood-entries/${id}`);
     },
-    onSuccess: () => {
+    onSuccess: (_data, id) => {
       void invalidateKeys(queryClient, moodDependentKeys);
+      toast.success(t("mood.deletedToast"), {
+        action: {
+          label: t("common.undo"),
+          onClick: () => void restoreEntries([id]),
+        },
+      });
     },
     // v1.11.5 — a failed delete used to fail silently (no onError handler),
     // leaving the row in place with no signal that the request was rejected.
@@ -268,19 +286,21 @@ export function MoodList({ onAddFirst }: MoodListProps = {}) {
   // v1.15.13 — page-scoped bulk soft-delete, mirroring the measurements list.
   const bulkDeleteMutation = useMutation({
     mutationFn: async (ids: string[]) => {
-      const res = await fetch("/api/mood-entries/bulk-delete", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ ids }),
-      });
-      if (!res.ok) throw new Error("Bulk delete failed");
-      const json = (await res.json()) as { data: { deleted: number } };
-      return json.data.deleted;
+      const data = await apiPost<{ deleted: number }>(
+        "/api/mood-entries/bulk-delete",
+        { ids },
+      );
+      return data.deleted;
     },
-    onSuccess: async (deleted) => {
+    onSuccess: async (deleted, ids) => {
       await invalidateKeys(queryClient, moodDependentKeys);
       clearSelection();
-      toast.success(t("mood.bulkDeleteSuccess", { count: String(deleted) }));
+      toast.success(t("mood.bulkDeleteSuccess", { count: String(deleted) }), {
+        action: {
+          label: t("common.undo"),
+          onClick: () => void restoreEntries(ids),
+        },
+      });
     },
     onError: () => {
       toast.error(t("mood.bulkDeleteError"));
@@ -324,16 +344,7 @@ export function MoodList({ onAddFirst }: MoodListProps = {}) {
       note: string | null;
       moodLoggedAt: string;
     }) => {
-      const res = await fetch(`/api/mood-entries/${id}`, {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ mood, tags, tagKeys, note, moodLoggedAt }),
-      });
-
-      const json = await res.json();
-      if (!res.ok) {
-        throw new Error(json.error ?? "Update failed");
-      }
+      await apiPut(`/api/mood-entries/${id}`, { mood, tags, tagKeys, note, moodLoggedAt });
     },
     onSuccess: async () => {
       await invalidateKeys(queryClient, moodDependentKeys);
diff --git a/src/components/mood/mood-tag-picker.tsx b/src/components/mood/mood-tag-picker.tsx
index b54440028..796b97aaf 100644
--- a/src/components/mood/mood-tag-picker.tsx
+++ b/src/components/mood/mood-tag-picker.tsx
@@ -7,6 +7,7 @@ import { useAuth } from "@/hooks/use-auth";
 import { queryKeys } from "@/lib/query-keys";
 import { useTranslations } from "@/lib/i18n/context";
 import { moodTagIcon } from "./mood-tag-icons";
+import { apiGet } from "@/lib/api/api-fetch";
 
 /**
  * v1.8.5 / v1.12.0 — structured mood-tag capture surface (Daylio-style).
@@ -78,10 +79,7 @@ export function MoodTagPicker({
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.moodTagCatalog(),
     queryFn: async () => {
-      const res = await fetch("/api/mood/tags");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as CatalogResponse;
+      return apiGet<CatalogResponse>("/api/mood/tags");
     },
     enabled: isAuthenticated,
     // The catalog only changes on a migration / admin edit.
diff --git a/src/components/onboarding/BaselineForm.tsx b/src/components/onboarding/BaselineForm.tsx
index f1ddbba08..ba933c755 100644
--- a/src/components/onboarding/BaselineForm.tsx
+++ b/src/components/onboarding/BaselineForm.tsx
@@ -19,7 +19,7 @@ import {
   SelectValue,
 } from "@/components/ui/select";
 import { useTranslations } from "@/lib/i18n/context";
-import { readError } from "@/lib/api/read-error";
+import { apiPost, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W14b-Content — onboarding step 3 (baseline).
@@ -90,20 +90,10 @@ export function BaselineForm() {
           profileBody.gender = form.gender;
         }
         if (Object.keys(profileBody).length > 0) {
-          const profileRes = await fetch("/api/auth/profile", {
-            method: "PUT",
-            headers: { "Content-Type": "application/json" },
-            body: JSON.stringify(profileBody),
-          });
-          if (!profileRes.ok) throw new Error(await readError(profileRes));
+          await apiPut("/api/auth/profile", profileBody);
         }
       }
-      const stepRes = await fetch("/api/onboarding/step", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ step: 4 }),
-      });
-      if (!stepRes.ok) throw new Error(await readError(stepRes));
+      await apiPost("/api/onboarding/step", { step: 4 });
       await queryClient.invalidateQueries({ queryKey: ["auth"] });
       router.push("/onboarding/4");
     } catch (err) {
diff --git a/src/components/onboarding/GoalsChipPicker.tsx b/src/components/onboarding/GoalsChipPicker.tsx
index 8274f834c..63708d0b3 100644
--- a/src/components/onboarding/GoalsChipPicker.tsx
+++ b/src/components/onboarding/GoalsChipPicker.tsx
@@ -17,8 +17,8 @@ import {
 
 import { Button } from "@/components/ui/button";
 import { useTranslations } from "@/lib/i18n/context";
-import { readError } from "@/lib/api/read-error";
 import { cn } from "@/lib/utils";
+import { apiPost } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W14b-Content — onboarding step 1 (goals).
@@ -122,12 +122,7 @@ export function GoalsChipPicker({ userId: _userId }: GoalsChipPickerProps) {
     if (advancing) return;
     setAdvancing(true);
     try {
-      const res = await fetch("/api/onboarding/step", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ step: 2 }),
-      });
-      if (!res.ok) throw new Error(await readError(res));
+      await apiPost("/api/onboarding/step", { step: 2 });
       await queryClient.invalidateQueries({ queryKey: ["auth"] });
       router.push("/onboarding/2");
     } catch (err) {
diff --git a/src/components/onboarding/SourceCardGrid.tsx b/src/components/onboarding/SourceCardGrid.tsx
index f4ea15554..0a225bfa5 100644
--- a/src/components/onboarding/SourceCardGrid.tsx
+++ b/src/components/onboarding/SourceCardGrid.tsx
@@ -15,8 +15,8 @@ import {
 
 import { Button } from "@/components/ui/button";
 import { useTranslations } from "@/lib/i18n/context";
-import { readError } from "@/lib/api/read-error";
 import { cn } from "@/lib/utils";
+import { apiPost } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W14b-Content — onboarding step 2 (source).
@@ -99,12 +99,7 @@ export function SourceCardGrid() {
     if (advancing) return;
     setAdvancing(true);
     try {
-      const res = await fetch("/api/onboarding/step", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ step: 3 }),
-      });
-      if (!res.ok) throw new Error(await readError(res));
+      await apiPost("/api/onboarding/step", { step: 3 });
       await queryClient.invalidateQueries({ queryKey: ["auth"] });
       router.push("/onboarding/3");
     } catch (err) {
diff --git a/src/components/onboarding/WelcomeCarousel.tsx b/src/components/onboarding/WelcomeCarousel.tsx
index b97146bd6..937e0fa0d 100644
--- a/src/components/onboarding/WelcomeCarousel.tsx
+++ b/src/components/onboarding/WelcomeCarousel.tsx
@@ -15,9 +15,9 @@ import {
 
 import { Button } from "@/components/ui/button";
 import { useTranslations } from "@/lib/i18n/context";
-import { readError } from "@/lib/api/read-error";
 import { scrollBehaviorForUser } from "@/lib/motion";
 import { cn } from "@/lib/utils";
+import { apiPost } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.25 W14b-Content — onboarding welcome carousel.
@@ -131,12 +131,7 @@ export function WelcomeCarousel() {
     if (advancing) return;
     setAdvancing(true);
     try {
-      const res = await fetch("/api/onboarding/step", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ step: 1 }),
-      });
-      if (!res.ok) throw new Error(await readError(res));
+      await apiPost("/api/onboarding/step", { step: 1 });
       await queryClient.invalidateQueries({ queryKey: ["auth"] });
       router.push("/onboarding/1");
     } catch (err) {
diff --git a/src/components/onboarding/getting-started-checklist.tsx b/src/components/onboarding/getting-started-checklist.tsx
index cdbdf9da1..ba1b2fe68 100644
--- a/src/components/onboarding/getting-started-checklist.tsx
+++ b/src/components/onboarding/getting-started-checklist.tsx
@@ -27,6 +27,7 @@ import {
   visibleChecklist,
   type ChecklistItemId,
 } from "@/lib/onboarding/checklist";
+import { apiGet } from "@/lib/api/api-fetch";
 
 const DISMISSED_ITEMS_KEY = "healthlog-getting-started-dismissed";
 const DISMISSED_ALL_KEY = "healthlog-getting-started-hidden";
@@ -213,10 +214,7 @@ export function GettingStartedChecklist() {
   const { data: medsData } = useQuery<Array<{ id: string }>>({
     queryKey: queryKeys.medications(),
     queryFn: async () => {
-      const res = await fetch("/api/medications");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data;
+      return apiGet("/api/medications");
     },
     enabled: checklistRelevant,
   });
@@ -232,10 +230,7 @@ export function GettingStartedChecklist() {
   const { data: withingsData } = useQuery<WithingsStatus>({
     queryKey: ["withings", "status"],
     queryFn: async () => {
-      const res = await fetch("/api/withings/status");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data;
+      return apiGet("/api/withings/status");
     },
     enabled: onboardingPending,
   });
@@ -243,10 +238,7 @@ export function GettingStartedChecklist() {
   const { data: notificationsData } = useQuery<NotificationsPreferences>({
     queryKey: ["notifications", "preferences"],
     queryFn: async () => {
-      const res = await fetch("/api/notifications/preferences");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data;
+      return apiGet("/api/notifications/preferences");
     },
     enabled: onboardingPending,
   });
@@ -329,7 +321,7 @@ export function GettingStartedChecklist() {
           aria-expanded={expanded}
           aria-controls="getting-started-body"
           // v1.4.37 W-CI — lift the toggle to clear the WCAG 2.5.5 mobile
-          // tap-target floor on Pixel-5 (Marc's iOS-textarea-zoom sweep
+          // tap-target floor on Pixel-5 (the maintainer's iOS-textarea-zoom sweep
           // pinned the floor at 44 px; the previous `p-1` padding left
           // the toggle at 32 px). `sm:min-h-10` returns to the desktop
           // 40 px tier so the dashboard header rhythm is unchanged.
diff --git a/src/components/onboarding/tour-launcher.tsx b/src/components/onboarding/tour-launcher.tsx
index f1fc4b694..73ade6e28 100644
--- a/src/components/onboarding/tour-launcher.tsx
+++ b/src/components/onboarding/tour-launcher.tsx
@@ -51,6 +51,7 @@ import { useEffect, useState } from "react";
 import { useQueryClient } from "@tanstack/react-query";
 
 import { useAuth } from "@/hooks/use-auth";
+import { apiPost } from "@/lib/api/api-fetch";
 import { OnboardingTour } from "./tour";
 
 const POST_WIZARD_GRACE_MS = 1500;
@@ -360,11 +361,7 @@ export function TourLauncher({ ready }: TourLauncherProps) {
         setShowTour(false);
         if (user?.id) writeSessionDismissed(user.id);
         try {
-          await fetch("/api/onboarding/tour", {
-            method: "POST",
-            headers: { "Content-Type": "application/json" },
-            body: JSON.stringify({ completed: true, outcome }),
-          });
+          await apiPost("/api/onboarding/tour", { completed: true, outcome });
           await queryClient.invalidateQueries({ queryKey: ["auth"] });
         } catch {
           // Swallow — the session-dismiss flag prevents a re-open.
diff --git a/src/components/providers.tsx b/src/components/providers.tsx
index 9f6167d22..59b2f89d5 100644
--- a/src/components/providers.tsx
+++ b/src/components/providers.tsx
@@ -114,9 +114,12 @@ function ThemeProvider({ children }: { children: ReactNode }) {
 export function Providers({
   children,
   initialLocale,
+  initialMessages,
 }: {
   children: ReactNode;
   initialLocale?: Locale;
+  /** Active locale's bundle, server-resolved by the root layout (RSC handoff). */
+  initialMessages?: Record<string, unknown>;
 }) {
   const [queryClient] = useState(
     () =>
@@ -135,7 +138,10 @@ export function Providers({
   return (
     <QueryClientProvider client={queryClient}>
       <ThemeProvider>
-        <I18nProvider initialLocale={initialLocale}>
+        <I18nProvider
+          initialLocale={initialLocale}
+          initialMessages={initialMessages}
+        >
           <AppSettingsProvider>
             {children}
             <Toaster position="bottom-right" richColors />
diff --git a/src/components/settings/__tests__/ai-section.test.tsx b/src/components/settings/__tests__/ai-section.test.tsx
index c3893e5ce..3df5f94a1 100644
--- a/src/components/settings/__tests__/ai-section.test.tsx
+++ b/src/components/settings/__tests__/ai-section.test.tsx
@@ -187,7 +187,7 @@ describe("<AiSection> — dropdown-driven UX (B2)", () => {
     expect(html).toContain("Mit ChatGPT verbinden");
     expect(html).toContain("ChatGPT-Account (Codex)");
     // v1.4.33 IW7 — the active-provider heading and the parent section
-    // both ship without the "KI"/"AI" prefix per the Marc-Voice rule
+    // both ship without the "KI"/"AI" prefix per the project-voice rule
     // ("Aktiver KI-Provider" → "Aktiver Provider"). The heading and the
     // chain summary now share the same phrase, so we assert against the
     // explicit `activeProviderLabel` slot below it ("Primärer Provider")
diff --git a/src/components/settings/__tests__/api-section-responsive.test.tsx b/src/components/settings/__tests__/api-section-responsive.test.tsx
index 66138197e..26243a3b0 100644
--- a/src/components/settings/__tests__/api-section-responsive.test.tsx
+++ b/src/components/settings/__tests__/api-section-responsive.test.tsx
@@ -61,8 +61,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       role: "USER",
     },
     isAuthenticated: true,
diff --git a/src/components/settings/__tests__/disable-coach-card.test.tsx b/src/components/settings/__tests__/disable-coach-card.test.tsx
index f6bd6973f..cb4468abf 100644
--- a/src/components/settings/__tests__/disable-coach-card.test.tsx
+++ b/src/components/settings/__tests__/disable-coach-card.test.tsx
@@ -44,7 +44,7 @@ vi.mock("next/navigation", () => ({
 function buildUser(disableCoach: boolean): AuthUser {
   return {
     id: "user-1",
-    username: "marc",
+    username: "testuser",
     email: null,
     role: "USER",
     heightCm: null,
@@ -134,7 +134,7 @@ describe("Settings — DisableCoachCard", () => {
 
   it("Switch description string matches the QoL audit (M2) copy", () => {
     const html = render();
-    // The Marc-voice contract: "Hides the Coach button and drawer
+    // The project-voice contract: "Hides the Coach button and drawer
     // everywhere." (English) — must surface verbatim because the QoL
     // findings doc cites this exact phrasing.
     expect(html).toContain("Hides the Coach button and drawer everywhere.");
diff --git a/src/components/settings/__tests__/integrations-section.test.tsx b/src/components/settings/__tests__/integrations-section.test.tsx
index e6e560f78..b26ef5596 100644
--- a/src/components/settings/__tests__/integrations-section.test.tsx
+++ b/src/components/settings/__tests__/integrations-section.test.tsx
@@ -1,7 +1,7 @@
 /**
  * v1.4.19 Phase A5 — Settings → Integrations status consolidation.
  *
- * the maintainer's verbatim concern (paraphrased):
+ * The maintainer's verbatim concern (paraphrased):
  *   - Withings card had 3 status displays — top-right "connected"
  *     badge, mid-card "connected / last successful / last attempt"
  *     trio container, and the badge inside that container.
diff --git a/src/components/settings/__tests__/sections.test.tsx b/src/components/settings/__tests__/sections.test.tsx
index 38845efad..6fa7f7c0e 100644
--- a/src/components/settings/__tests__/sections.test.tsx
+++ b/src/components/settings/__tests__/sections.test.tsx
@@ -52,8 +52,8 @@ vi.mock("@/hooks/use-auth", () => ({
   useAuth: () => ({
     user: {
       id: "u1",
-      username: "marc",
-      email: "marc@example.com",
+      username: "testuser",
+      email: "user@example.com",
       heightCm: 180,
       dateOfBirth: "1990-01-01",
       gender: "MALE",
@@ -153,7 +153,7 @@ describe("settings sections — SSR smoke", () => {
   });
 
   it("<AboutSection> renders the German Replay-tour label end-to-end", () => {
-    // Marc-voice + i18n parity: the W5 spec explicitly names this
+    // project-voice + i18n parity: the W5 spec explicitly names this
     // surface "Tour ansehen" in German. Lock the resolved copy so a
     // future locale-bundle drift doesn't silently fall back to English.
     const html = render(<AboutSection />, "de");
diff --git a/src/components/settings/about-me-section.tsx b/src/components/settings/about-me-section.tsx
index 3d70e6c1a..3afa805e6 100644
--- a/src/components/settings/about-me-section.tsx
+++ b/src/components/settings/about-me-section.tsx
@@ -37,6 +37,7 @@ import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { cn } from "@/lib/utils";
+import { apiGet, apiPut } from "@/lib/api/api-fetch";
 
 const FALLBACK_MAX_CHARS = 4000;
 const FALLBACK_FIELD_MAX_CHARS = 500;
@@ -55,11 +56,7 @@ interface AboutMeData {
 type StructuredKey = "conditions" | "allergies" | "coachFocus";
 
 async function fetchAboutMe(): Promise<AboutMeData> {
-  const res = await fetch("/api/coach/about-me");
-  if (!res.ok) {
-    throw new Error(`HTTP ${res.status}`);
-  }
-  return (await res.json()).data as AboutMeData;
+  return apiGet<AboutMeData>("/api/coach/about-me");
 }
 
 const FIELD_CLASSES =
@@ -129,15 +126,7 @@ export function AboutMeSection({
       allergies: string;
       coachFocus: string;
     }) => {
-      const res = await fetch("/api/coach/about-me", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(input),
-      });
-      if (!res.ok) {
-        throw new Error(`HTTP ${res.status}`);
-      }
-      return (await res.json()).data as AboutMeData;
+      return apiPut<AboutMeData>("/api/coach/about-me", input);
     },
     onSuccess: (next) => {
       const cleared =
diff --git a/src/components/settings/about-section.tsx b/src/components/settings/about-section.tsx
index 0c11895d6..2bb6127dd 100644
--- a/src/components/settings/about-section.tsx
+++ b/src/components/settings/about-section.tsx
@@ -19,6 +19,7 @@ import { useAuth } from "@/hooks/use-auth";
 import { useFormatters, useTranslations } from "@/lib/i18n/context";
 import { restartOnboardingTour } from "@/lib/onboarding/tour-restart";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface VersionPayload {
   version: string;
@@ -129,10 +130,7 @@ export function AboutSection() {
   const { data: version, isLoading } = useQuery({
     queryKey: queryKeys.apiVersion(),
     queryFn: async () => {
-      const res = await fetch("/api/version");
-      if (!res.ok) throw new Error("version-fetch-failed");
-      const json = await res.json();
-      return json.data as VersionPayload;
+      return apiGet<VersionPayload>("/api/version");
     },
     // The endpoint is `force-static` — version doesn't change at runtime.
     staleTime: Infinity,
@@ -187,7 +185,7 @@ export function AboutSection() {
 
   async function runCheck(): Promise<void> {
     try {
-      const res = await fetch("/api/version/check-updates");
+      const res = await apiFetchRaw("/api/version/check-updates");
       if (!res.ok) {
         setUpdateResult({
           status: "unknown",
diff --git a/src/components/settings/account-section.tsx b/src/components/settings/account-section.tsx
index d646b0a3b..4e4f1259b 100644
--- a/src/components/settings/account-section.tsx
+++ b/src/components/settings/account-section.tsx
@@ -55,6 +55,7 @@ import { UnitPreferenceSelect } from "@/components/settings/unit-preference-sele
 import { InjectionSitesCard } from "@/components/settings/injection-sites-card";
 import { CycleTrackingCard } from "@/components/settings/cycle-tracking-card";
 import { detectBrowserTimezone, DEFAULT_TIMEZONE } from "@/lib/tz/format";
+import { apiDelete, apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface PasskeyInfo {
   id: string;
@@ -110,7 +111,7 @@ export function resolveInitialTimezone(
 }
 
 export function AccountSection() {
-  const { t, locale, setLocale } = useTranslations();
+  const { t, locale, setLocale, pendingLocale } = useTranslations();
   const { user, isLoading, isAuthenticated, refetch } = useAuth();
   const router = useRouter();
 
@@ -204,7 +205,7 @@ export function AccountSection() {
     // through the bigger profile patch path. Run the two PUTs in
     // parallel — they're independent.
     const [profileRes, tzRes] = await Promise.all([
-      fetch("/api/auth/profile", {
+      apiFetchRaw("/api/auth/profile", {
         method: "PUT",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
@@ -218,7 +219,7 @@ export function AccountSection() {
         }),
       }),
       user && timezone && timezone !== user.timezone
-        ? fetch("/api/auth/me/timezone", {
+        ? apiFetchRaw("/api/auth/me/timezone", {
             method: "PUT",
             headers: { "Content-Type": "application/json" },
             body: JSON.stringify({ timezone }),
@@ -256,7 +257,7 @@ export function AccountSection() {
     setPasskeyMsgType(null);
 
     try {
-      const optRes = await fetch("/api/auth/passkey/register-options", {
+      const optRes = await apiFetchRaw("/api/auth/passkey/register-options", {
         method: "POST",
       });
 
@@ -273,7 +274,7 @@ export function AccountSection() {
       const { startRegistration } = await import("@simplewebauthn/browser");
       const credential = await startRegistration({ optionsJSON: options });
 
-      const verifyRes = await fetch("/api/auth/passkey/register-verify", {
+      const verifyRes = await apiFetchRaw("/api/auth/passkey/register-verify", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({ challengeId, credential }),
@@ -335,7 +336,7 @@ export function AccountSection() {
     }
 
     try {
-      const res = await fetch("/api/auth/password", {
+      const res = await apiFetchRaw("/api/auth/password", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
@@ -490,9 +491,15 @@ export function AccountSection() {
             </div>
             <div className="space-y-2">
               <Label htmlFor="language-select">{t("settings.language")}</Label>
+              {/* While a switch waits on its message bundle (dynamic
+                  import per locale), show the target value and lock the
+                  control — the context only flips locale + strings
+                  together once the bundle arrived. */}
               <NativeSelect
                 id="language-select"
-                value={locale}
+                value={pendingLocale ?? locale}
+                disabled={pendingLocale !== null}
+                aria-busy={pendingLocale !== null}
                 onChange={(e) => setLocale(e.target.value as Locale)}
               >
                 {locales.map((loc) => (
@@ -817,18 +824,14 @@ function PasskeyListSection({ isAuthenticated }: { isAuthenticated: boolean }) {
   const { data: passkeys } = useQuery({
     queryKey: queryKeys.passkeys(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/passkeys");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as PasskeyInfo[];
+      return apiGet<PasskeyInfo[]>("/api/auth/passkeys");
     },
     enabled: isAuthenticated,
   });
 
   const deletePasskey = useMutation({
     mutationFn: async (id: string) => {
-      const res = await fetch(`/api/auth/passkeys/${id}`, { method: "DELETE" });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("common.error"));
+      await apiDelete(`/api/auth/passkeys/${id}`);
     },
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: queryKeys.passkeys() });
@@ -1088,7 +1091,10 @@ function AvatarSection() {
     mutationFn: async (file: File) => {
       const body = new FormData();
       body.append("file", file);
-      const res = await fetch("/api/user/avatar", { method: "POST", body });
+      const res = await apiFetchRaw("/api/user/avatar", {
+        method: "POST",
+        body,
+      });
       const json = await res.json().catch(() => ({}));
       if (!res.ok) {
         if (res.status === 415)
@@ -1110,7 +1116,7 @@ function AvatarSection() {
 
   const remove = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/user/avatar", { method: "DELETE" });
+      const res = await apiFetchRaw("/api/user/avatar", { method: "DELETE" });
       if (!res.ok) {
         const json = await res.json().catch(() => ({}));
         throw new Error(json.error || t("settings.avatar.error"));
diff --git a/src/components/settings/advanced-section.tsx b/src/components/settings/advanced-section.tsx
index 38a6c6a1e..22fa1c307 100644
--- a/src/components/settings/advanced-section.tsx
+++ b/src/components/settings/advanced-section.tsx
@@ -25,6 +25,7 @@ import {
   type ResearchModeStatus,
   researchModeGateState,
 } from "@/lib/medications/research-mode-types";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
 
 /**
  * Settings → Advanced.
@@ -104,7 +105,7 @@ function ResearchModeCard() {
   const { data: status, isLoading } = useQuery<ResearchModeStatus | null>({
     queryKey: queryKeys.researchMode(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/me/research-mode");
+      const res = await apiFetchRaw("/api/auth/me/research-mode");
       if (!res.ok) return null;
       const json = await res.json();
       return json.data as ResearchModeStatus;
@@ -133,7 +134,7 @@ function ResearchModeCard() {
     // Toggle OFF → fire DELETE directly.
     setToggleBusy(true);
     try {
-      const res = await fetch("/api/auth/me/research-mode", {
+      const res = await apiFetchRaw("/api/auth/me/research-mode", {
         method: "DELETE",
       });
       if (!res.ok) {
@@ -243,7 +244,7 @@ function DataResetCard() {
     setMsg(null);
     setMsgType(null);
     try {
-      const res = await fetch("/api/settings/data", {
+      const res = await apiFetchRaw("/api/settings/data", {
         method: "DELETE",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({ confirm: "DELETE" }),
@@ -383,7 +384,7 @@ function AccountDeleteCard() {
     setMsg(null);
     setMsgType(null);
     try {
-      const res = await fetch("/api/settings/account", {
+      const res = await apiFetchRaw("/api/settings/account", {
         method: "DELETE",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({ confirm: "DELETE_ACCOUNT" }),
diff --git a/src/components/settings/ai-section.tsx b/src/components/settings/ai-section.tsx
index 6c132e8c5..19fa3722d 100644
--- a/src/components/settings/ai-section.tsx
+++ b/src/components/settings/ai-section.tsx
@@ -1,176 +1,22 @@
 "use client";
 
-import { useEffect, useMemo, useRef, useState } from "react";
-import { usePathname, useRouter, useSearchParams } from "next/navigation";
-import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
-import {
-  ArrowDown,
-  ArrowUp,
-  Loader2,
-  PlusCircle,
-  RefreshCw,
-  RotateCcw,
-  Save,
-  Sparkles,
-  Trash2,
-  X,
-} from "lucide-react";
+/**
+ * Settings → AI section wrapper.
+ *
+ * v1.16.4 — the former 2k-LOC monolith is split into per-provider
+ * subcomponents under `src/components/settings/ai/` (one file per
+ * provider form, plus the chain / runtime / coach-toggle cards). This
+ * file only owns the section frame and the card order; behaviour lives
+ * in the parts.
+ */
 
-import {
-  AlertDialog,
-  AlertDialogAction,
-  AlertDialogCancel,
-  AlertDialogContent,
-  AlertDialogDescription,
-  AlertDialogFooter,
-  AlertDialogHeader,
-  AlertDialogTitle,
-  AlertDialogTrigger,
-} from "@/components/ui/alert-dialog";
-import { Badge } from "@/components/ui/badge";
-import { Button } from "@/components/ui/button";
-import { Input } from "@/components/ui/input";
-import { Label } from "@/components/ui/label";
-import { NativeSelect } from "@/components/ui/native-select";
-import { Switch } from "@/components/ui/switch";
-import { PasswordInput } from "@/components/ui/password-input";
 import { AboutMeSection } from "@/components/settings/about-me-section";
-import { SettingsCardHeader } from "@/components/settings/_card-header";
+import { AiInsightsCard } from "@/components/settings/ai/ai-insights-card";
+import { DisableCoachCard } from "@/components/settings/ai/disable-coach-card";
 import { CoachMemorySection } from "@/components/settings/coach-memory-section";
 import { CoachPrefsSection } from "@/components/settings/coach-prefs-section";
 import { useAuth } from "@/hooks/use-auth";
-import { formatDateTime } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
-import { queryKeys } from "@/lib/query-keys";
-import { toast } from "sonner";
-
-interface InsightsSettings {
-  codexStatus: string;
-  codexConnectedAt: string | null;
-  hasAdminKey: boolean;
-  /** True when the operator has set `CODEX_OAUTH_CLIENT_ID` on this
-   *  instance. The UI hides the "Connect with ChatGPT" button when
-   *  false to avoid the v1.4.2 dead-end where the click bounced the
-   *  user to chatgpt.com without any OAuth flow. */
-  codexOauthConfigured?: boolean;
-  privacyMode: string;
-  lastInsightAt: string | null;
-}
-
-interface UserAIProvider {
-  provider: string | null;
-  model: string | null;
-  baseUrl: string | null;
-  hasAnthropicKey: boolean;
-  anthropicKeyPreview: string | null;
-  hasLocalKey: boolean;
-  hasOpenaiKey: boolean;
-  openaiKeyPreview: string | null;
-}
-
-/**
- * v1.4.16 phase B2 — provider tags exposed to the UI. Mirrors
- * `PROVIDER_CHAIN_TYPES` server-side; kept as a const-array here to
- * avoid pulling a server-only module into the client bundle.
- */
-const PROVIDER_TYPES = [
-  "codex",
-  "openai",
-  "anthropic",
-  "local",
-  "admin-openai",
-] as const;
-type ProviderType = (typeof PROVIDER_TYPES)[number];
-
-interface ChainEntry {
-  providerType: ProviderType;
-  enabled: boolean;
-}
-
-interface ProviderChainData {
-  activeProvider: ProviderType | null;
-  cachedActiveProvider: ProviderType | null;
-  configuredChain: {
-    providerType: ProviderType;
-    enabled: boolean;
-    available: boolean;
-  }[];
-}
-
-const DEFAULT_CHAIN: readonly ChainEntry[] = [
-  { providerType: "codex", enabled: true },
-  { providerType: "openai", enabled: true },
-  { providerType: "anthropic", enabled: true },
-  { providerType: "local", enabled: true },
-  { providerType: "admin-openai", enabled: true },
-];
-
-/**
- * OpenAI model presets — the wire-up keeps users out of the freetext
- * box for the common case. The `__custom__` sentinel surfaces a
- * freetext input so power users can target preview models or
- * fine-tunes (e.g. `gpt-5`, which is admitted via the env override on
- * the Codex backend but not yet a documented OpenAI model id).
- */
-const OPENAI_MODEL_PRESETS = ["gpt-4o", "gpt-4o-mini", "gpt-4-turbo"] as const;
-const ANTHROPIC_MODEL_PRESETS = [
-  "claude-sonnet-4-6",
-  "claude-opus-4-7",
-  "claude-haiku-4-5",
-  "claude-3-5-sonnet-latest",
-] as const;
-const LOCAL_MODEL_PRESETS = [
-  "llama3.1:8b",
-  "llama3.1:70b",
-  "mistral",
-  "qwen2.5",
-] as const;
-const CUSTOM_MODEL_SENTINEL = "__custom__";
-
-/**
- * Map UI provider tag → the `aiProvider` enum understood by the
- * legacy single-result `resolveProvider()` resolver. `codex` and
- * `admin-openai` aren't user-level provider columns (they're handled
- * by Codex OAuth + admin-key fallback), so they map to null and the
- * legacy column is left blank.
- */
-function uiToLegacyProviderEnum(p: ProviderType): string | null {
-  switch (p) {
-    case "openai":
-      return "OPENAI";
-    case "anthropic":
-      return "ANTHROPIC";
-    case "local":
-      return "LOCAL";
-    case "codex":
-    case "admin-openai":
-    default:
-      return null;
-  }
-}
-
-// Map the connection-test failure category (a stable, secret-free code from
-// /api/ai/test) to a localised message. Falls back to the server's plain
-// English `reason` for any unmapped / legacy code so a German operator never
-// sees an untranslated sentence in the otherwise-localised Settings panel.
-function localiseTestReason(
-  t: (key: string, params?: Record<string, string | number>) => string,
-  reasonCode: string | undefined,
-  reason: string | undefined,
-): string | undefined {
-  switch (reasonCode) {
-    case "credentials":
-      return t("settings.ai.testReasonCredentials");
-    case "rate_limited":
-      return t("settings.ai.testReasonRateLimited");
-    case "server_error":
-      return t("settings.ai.testReasonServerError");
-    case "unreachable":
-      return t("settings.ai.testReasonUnreachable");
-    default:
-      return reason;
-  }
-}
 
 export function AiSection() {
   const { t } = useTranslations();
@@ -218,1800 +64,3 @@ export function AiSection() {
     </section>
   );
 }
-
-/**
- * v1.4.47 W3 — "Hide Coach" toggle card.
- *
- * Persists via `PATCH /api/auth/me/disable-coach`; the response
- * invalidates `queryKeys.authMe()` so every Coach mount point on the
- * client (`<LayoutCoachFab>`, `<LayoutCoachMount>`, the inline
- * `<CoachLaunchButton>` pill, the `/targets` page CTAs) re-renders
- * with the new `user.disableCoach` value on the next React Query
- * refetch tick — no full reload required.
- *
- * The optimistic-update pattern mirrors `<MoodReminderCard>`: the
- * Switch flips immediately, the mutation rolls back on error.
- */
-function DisableCoachCard({ isAuthenticated }: { isAuthenticated: boolean }) {
-  const { t } = useTranslations();
-  const queryClient = useQueryClient();
-  const { user } = useAuth();
-
-  // Optimistic-update flag — null means "no in-flight change",
-  // otherwise it overrides the wire value until the mutation
-  // settles. Mirrors the `<MoodReminderCard>` pattern so the Switch
-  // reacts instantly to the user's tap.
-  const [optimistic, setOptimistic] = useState<boolean | null>(null);
-  const [msg, setMsg] = useState<string | null>(null);
-  const [msgType, setMsgType] = useState<"success" | "error" | null>(null);
-
-  // v1.4.48 M2 — auto-clear the inline `<p role="status">` line 3 s
-  // after the mutation settles so a Settings card the user scrolled
-  // past minutes earlier doesn't keep echoing a stale "Coach hidden"
-  // banner. The ref tracks the in-flight timer so we can clear it on
-  // unmount + on a follow-up toggle (otherwise a rapid double-tap
-  // could leave a stray timer pointing at a stale message).
-  const clearTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
-
-  useEffect(() => {
-    return () => {
-      if (clearTimerRef.current !== null) {
-        clearTimeout(clearTimerRef.current);
-        clearTimerRef.current = null;
-      }
-    };
-  }, []);
-
-  function scheduleClear() {
-    if (clearTimerRef.current !== null) {
-      clearTimeout(clearTimerRef.current);
-    }
-    clearTimerRef.current = setTimeout(() => {
-      clearTimerRef.current = null;
-      setMsg(null);
-      setMsgType(null);
-    }, 3000);
-  }
-
-  const checked = optimistic ?? user?.disableCoach ?? false;
-
-  const mutation = useMutation({
-    mutationFn: async (next: boolean) => {
-      const res = await fetch("/api/auth/me/disable-coach", {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ disableCoach: next }),
-      });
-      if (!res.ok) {
-        const json = (await res.json().catch(() => ({}))) as {
-          error?: string;
-        };
-        throw new Error(json.error ?? `HTTP ${res.status}`);
-      }
-      return next;
-    },
-    onSuccess: (next) => {
-      setMsg(
-        next
-          ? t("settings.ai.disableCoach.savedHidden")
-          : t("settings.ai.disableCoach.savedShown"),
-      );
-      setMsgType("success");
-      // Surface the new value to every Coach gate via the shared
-      // `useAuth()` query — the gates re-render once React Query
-      // re-fetches /api/auth/me with the updated `disableCoach` field.
-      queryClient.invalidateQueries({ queryKey: queryKeys.authMe() });
-      setOptimistic(null);
-      scheduleClear();
-    },
-    onError: (err) => {
-      setOptimistic(null);
-      setMsg(
-        err instanceof Error
-          ? err.message
-          : t("settings.ai.disableCoach.saveError"),
-      );
-      setMsgType("error");
-      scheduleClear();
-    },
-  });
-
-  function handleToggle(next: boolean) {
-    setOptimistic(next);
-    setMsg(null);
-    setMsgType(null);
-    if (clearTimerRef.current !== null) {
-      clearTimeout(clearTimerRef.current);
-      clearTimerRef.current = null;
-    }
-    mutation.mutate(next);
-  }
-
-  return (
-    <section
-      aria-labelledby="settings-ai-disable-coach-title"
-      data-testid="settings-disable-coach-card"
-      className="bg-card border-border space-y-3 rounded-xl border p-6"
-    >
-      <div className="flex items-center justify-between gap-4">
-        <div className="pr-2">
-          <h2
-            id="settings-ai-disable-coach-title"
-            className="text-base font-semibold"
-          >
-            {t("settings.ai.disableCoach.title")}
-          </h2>
-          <p className="text-muted-foreground text-xs">
-            {t("settings.ai.disableCoach.description")}
-          </p>
-        </div>
-        <Switch
-          data-testid="settings-disable-coach-switch"
-          checked={checked}
-          onCheckedChange={handleToggle}
-          disabled={!isAuthenticated || mutation.isPending}
-          aria-label={t("settings.ai.disableCoach.toggleAria")}
-        />
-      </div>
-      {msg && (
-        <p
-          role="status"
-          aria-live="polite"
-          className={
-            msgType === "error"
-              ? "text-destructive text-xs"
-              : "text-muted-foreground text-xs"
-          }
-        >
-          {msg}
-        </p>
-      )}
-    </section>
-  );
-}
-
-/**
- * The single dropdown-driven configuration card. Replaces the
- * v1.4.15-vintage two-card layout (Codex connect at the top, personal
- * provider form at the bottom) per the maintainer's
- * `feedback_settings_no_split.md`: one provider Select, one matching
- * form below, one fallback-chain card at the bottom.
- *
- * The active-provider Select is URL-synced via `?provider=…` so deep
- * links to a specific config form work, the SSR test can drive the
- * branch deterministically, and a refresh keeps the user on the form
- * they were editing.
- */
-function AiInsightsCard({ isAuthenticated }: { isAuthenticated: boolean }) {
-  const { t } = useTranslations();
-  const queryClient = useQueryClient();
-  const router = useRouter();
-  const pathname = usePathname();
-  const searchParams = useSearchParams();
-
-  const { data: insightsSettings } = useQuery({
-    queryKey: queryKeys.insightsSettings(),
-    queryFn: async () => {
-      const res = await fetch("/api/insights/settings");
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as InsightsSettings;
-    },
-    enabled: isAuthenticated,
-  });
-
-  const { data: userProvider } = useQuery({
-    queryKey: queryKeys.userAiProvider(),
-    queryFn: async () => {
-      const res = await fetch("/api/user/ai-provider");
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as UserAIProvider;
-    },
-    enabled: isAuthenticated,
-  });
-
-  const { data: chainData } = useQuery({
-    queryKey: queryKeys.insightsProviderChain(),
-    queryFn: async () => {
-      const res = await fetch("/api/insights/provider-chain");
-      if (!res.ok) return null;
-      const json = await res.json();
-      return json.data as ProviderChainData;
-    },
-    enabled: isAuthenticated,
-  });
-
-  // The Select is URL-driven so the SSR test can pick the branch and
-  // a deep link works. Default = `?provider=…` query param when the
-  // user navigated here intentionally, else the chain's active entry,
-  // else "codex". The seed-on-data-arrival pattern below avoids
-  // setState-in-effect (lint rule `react-hooks/set-state-in-effect`)
-  // by reading the resolved value at render time and consulting a
-  // `seededFor` marker so we only re-seed when the relevant inputs
-  // actually changed.
-  const queryProvider = searchParams?.get("provider") ?? null;
-  const [selectedProvider, setSelectedProvider] = useState<ProviderType>(() =>
-    isProviderType(queryProvider) ? queryProvider : "codex",
-  );
-  const seedKey = `${queryProvider ?? ""}|${chainData?.activeProvider ?? ""}`;
-  const [seededFor, setSeededFor] = useState<string>(seedKey);
-  if (seedKey !== seededFor) {
-    setSeededFor(seedKey);
-    if (isProviderType(queryProvider)) {
-      setSelectedProvider(queryProvider);
-    } else if (chainData?.activeProvider) {
-      setSelectedProvider(chainData.activeProvider);
-    }
-  }
-
-  function pickProvider(next: ProviderType) {
-    setSelectedProvider(next);
-    if (typeof window === "undefined") return;
-    const params = new URLSearchParams(searchParams?.toString() ?? "");
-    params.set("provider", next);
-    router.replace(`${pathname}?${params.toString()}`);
-  }
-
-  return (
-    <div className="bg-card border-border space-y-4 rounded-xl border p-6">
-      {/* The card used to render an icon-only header row (Sparkles +
-          status badges, no title), which left the tile unanchored next
-          to its titled siblings. It now follows the shared
-          `SettingsCardHeader` contract: icon column, title + description
-          in the content column, status badges top-right — and the body
-          below indents to the title column (`pl-7`). */}
-      <SettingsCardHeader
-        icon={Sparkles}
-        title={t("settings.ai.providerCardTitle")}
-        description={t("settings.kiInsightsDescription")}
-        status={
-          <ProviderStatusBadges
-            settings={insightsSettings}
-            activeProvider={chainData?.activeProvider ?? null}
-          />
-        }
-      />
-
-      <div className="space-y-4 pl-7">
-        <ActiveProviderSelect
-          value={selectedProvider}
-          onChange={pickProvider}
-        />
-
-        <ProviderConfigCard
-          provider={selectedProvider}
-          insightsSettings={insightsSettings}
-          userProvider={userProvider}
-        />
-
-        <FallbackChainCard
-          chain={chainData?.configuredChain ?? []}
-          selected={selectedProvider}
-          onSelect={pickProvider}
-        />
-
-        <RuntimeActionsRow
-          provider={selectedProvider}
-          userProvider={userProvider}
-          canRegenerate={
-            insightsSettings?.codexStatus === "connected" ||
-            insightsSettings?.hasAdminKey ||
-            Boolean(userProvider?.provider)
-          }
-          privacyMode={insightsSettings?.privacyMode ?? "aggregated"}
-          lastInsightAt={insightsSettings?.lastInsightAt ?? null}
-          onRegenerated={() =>
-            queryClient.invalidateQueries({
-              queryKey: queryKeys.insightsRoot(),
-            })
-          }
-          onPrivacyChanged={() =>
-            queryClient.invalidateQueries({
-              queryKey: queryKeys.insightsRoot(),
-            })
-          }
-        />
-      </div>
-    </div>
-  );
-}
-
-function isProviderType(v: string | null): v is ProviderType {
-  return v != null && (PROVIDER_TYPES as readonly string[]).includes(v);
-}
-
-function ProviderStatusBadges({
-  settings,
-  activeProvider,
-}: {
-  settings: InsightsSettings | null | undefined;
-  activeProvider: ProviderType | null;
-}) {
-  const { t } = useTranslations();
-  return (
-    <div className="flex flex-wrap items-center gap-2">
-      {settings?.codexStatus === "connected" && activeProvider === "codex" && (
-        <Badge className="border-success/30 bg-success/15 text-success">
-          {t("settings.ai.chatgptConnectedBadge")}
-        </Badge>
-      )}
-      {settings?.codexStatus !== "connected" &&
-        settings?.hasAdminKey &&
-        activeProvider !== "codex" && (
-          <Badge className="border-primary/30 bg-primary/15 text-primary">
-            {t("settings.ai.adminAiActiveBadge")}
-          </Badge>
-        )}
-      {settings?.codexStatus === "expired" && (
-        <Badge className="border-warning/30 bg-warning/15 text-warning">
-          {t("settings.ai.connectionExpiredBadge")}
-        </Badge>
-      )}
-      {settings?.lastInsightAt && (
-        <Badge variant="outline" className="text-xs">
-          {t("settings.lastGeneratedAt")}:{" "}
-          {formatDateTime(settings.lastInsightAt)}
-        </Badge>
-      )}
-    </div>
-  );
-}
-
-/**
- * The single Pulldown that drives every form below it. Uses the
- * shared `<NativeSelect>` primitive so the SSR-only settings test
- * renders deterministically without a portal-based Radix tree, and so
- * the visual contract stays uniform with the other settings pickers
- * that landed behind the same primitive in MB7 / CF-52. Mobile:
- * full-width, height matched to the shared 36 px input contract used
- * everywhere else in Settings; tap target stays comfortable thanks to
- * the full-width chevron region.
- */
-function ActiveProviderSelect({
-  value,
-  onChange,
-}: {
-  value: ProviderType;
-  onChange: (next: ProviderType) => void;
-}) {
-  const { t } = useTranslations();
-  return (
-    <div className="bg-muted/50 rounded-lg p-4">
-      <p className="text-sm font-medium">
-        {t("settings.ai.activeProviderHeading")}
-      </p>
-      <p className="text-muted-foreground mb-3 text-xs">
-        {t("settings.ai.activeProviderBody")}
-      </p>
-      <Label htmlFor="ai-active-provider-select">
-        {t("settings.ai.activeProviderLabel")}
-      </Label>
-      <NativeSelect
-        id="ai-active-provider-select"
-        data-testid="ai-active-provider-select"
-        value={value}
-        onChange={(e) => {
-          const next = e.target.value;
-          if (isProviderType(next)) onChange(next);
-        }}
-        className="mt-1 sm:max-w-md"
-      >
-        {PROVIDER_TYPES.map((p) => (
-          <option key={p} value={p}>
-            {t(`settings.ai.providerSelect.${p}` as const)}
-          </option>
-        ))}
-      </NativeSelect>
-    </div>
-  );
-}
-
-/**
- * Switch-rendered provider configuration. The component is the
- * "form below adapts dynamically" half of the maintainer's pulldown contract:
- * pick Codex → see Codex form; pick OpenAI → see API-key + model
- * dropdown + base-URL override. The card frame is the same in every
- * branch so transitions feel like updating a single concept rather
- * than swapping pages.
- */
-function ProviderConfigCard({
-  provider,
-  insightsSettings,
-  userProvider,
-}: {
-  provider: ProviderType;
-  insightsSettings: InsightsSettings | null | undefined;
-  userProvider: UserAIProvider | null | undefined;
-}) {
-  const { t } = useTranslations();
-  return (
-    <div className="bg-muted/50 space-y-4 rounded-lg p-4">
-      <p className="text-sm font-medium">
-        {t("settings.ai.providerConfigTitle")}
-      </p>
-      {provider === "codex" && (
-        <CodexProviderForm settings={insightsSettings} />
-      )}
-      {provider === "openai" && (
-        <OpenAIProviderForm userProvider={userProvider} />
-      )}
-      {provider === "anthropic" && (
-        <AnthropicProviderForm userProvider={userProvider} />
-      )}
-      {provider === "local" && (
-        <LocalProviderForm userProvider={userProvider} />
-      )}
-      {provider === "admin-openai" && (
-        <AdminOpenAIProviderForm hasAdminKey={insightsSettings?.hasAdminKey} />
-      )}
-    </div>
-  );
-}
-
-/* ────────────────────────────────────────────────────────────────
- * Codex (ChatGPT account) form — connect / disconnect / status.
- * ──────────────────────────────────────────────────────────────── */
-
-function CodexProviderForm({
-  settings,
-}: {
-  settings: InsightsSettings | null | undefined;
-}) {
-  const { t } = useTranslations();
-  const queryClient = useQueryClient();
-
-  const [msg, setMsg] = useState<string | null>(null);
-  const [msgType, setMsgType] = useState<"success" | "error" | null>(null);
-  const [disconnecting, setDisconnecting] = useState(false);
-  const [deviceCode, setDeviceCode] = useState<{
-    userCode: string;
-    verificationUrl: string;
-    intervalSeconds: number;
-  } | null>(null);
-  const [devicePolling, setDevicePolling] = useState(false);
-
-  // OAuth callback handler — reads `?codex_connected=true|codex_error=…`
-  // from the URL and surfaces an inline message.
-  const [oauthOutcome] = useState<
-    { kind: "connected" } | { kind: "error" } | null
-  >(() => {
-    if (typeof window === "undefined") return null;
-    const params = new URLSearchParams(window.location.search);
-    if (params.get("codex_connected") === "true") return { kind: "connected" };
-    if (params.get("codex_error")) return { kind: "error" };
-    return null;
-  });
-
-  useEffect(() => {
-    if (!oauthOutcome) return;
-    const url = new URL(window.location.href);
-    url.searchParams.delete("codex_connected");
-    url.searchParams.delete("codex_error");
-    window.history.replaceState({}, "", url.toString());
-    if (oauthOutcome.kind === "connected") {
-      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
-    }
-  }, [oauthOutcome, queryClient]);
-
-  const [oauthMsgSeeded, setOauthMsgSeeded] = useState(false);
-  if (!oauthMsgSeeded && oauthOutcome) {
-    setOauthMsgSeeded(true);
-    if (oauthOutcome.kind === "connected") {
-      setMsg(t("settings.codexConnected"));
-      setMsgType("success");
-    } else {
-      setMsg(t("settings.codexConnectionFailed"));
-      setMsgType("error");
-    }
-  }
-
-  async function handleConnect() {
-    setMsg(null);
-    setDevicePolling(true);
-    try {
-      const res = await fetch("/api/auth/codex/device-start", {
-        method: "POST",
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("settings.savingError"));
-      setDeviceCode({
-        userCode: json.data.userCode,
-        verificationUrl: json.data.verificationUrl,
-        intervalSeconds: json.data.intervalSeconds,
-      });
-    } catch (err) {
-      setMsg(err instanceof Error ? err.message : t("settings.savingError"));
-      setMsgType("error");
-      setDevicePolling(false);
-    }
-  }
-
-  useEffect(() => {
-    if (!deviceCode) return;
-    let cancelled = false;
-    const intervalMs = Math.max(deviceCode.intervalSeconds, 3) * 1000;
-
-    async function tick() {
-      try {
-        const res = await fetch("/api/auth/codex/device-poll", {
-          method: "POST",
-        });
-        const json = await res.json();
-        if (cancelled) return;
-        if (!res.ok) {
-          throw new Error(json.error || t("settings.savingError"));
-        }
-        if (json.data?.status === "connected") {
-          setDeviceCode(null);
-          setDevicePolling(false);
-          setMsg(t("settings.codexConnected"));
-          setMsgType("success");
-          queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
-          return;
-        }
-        if (!cancelled) setTimeout(tick, intervalMs);
-      } catch (err) {
-        if (cancelled) return;
-        setMsg(err instanceof Error ? err.message : t("settings.savingError"));
-        setMsgType("error");
-        setDeviceCode(null);
-        setDevicePolling(false);
-      }
-    }
-
-    const handle = setTimeout(tick, intervalMs);
-    return () => {
-      cancelled = true;
-      clearTimeout(handle);
-    };
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [deviceCode]);
-
-  function handleCancelDevice() {
-    setDeviceCode(null);
-    setDevicePolling(false);
-  }
-
-  async function handleDisconnect() {
-    setDisconnecting(true);
-    setMsg(null);
-    try {
-      const res = await fetch("/api/auth/codex/disconnect", {
-        method: "DELETE",
-      });
-      if (!res.ok) {
-        const json = await res.json();
-        throw new Error(json.error);
-      }
-      setMsg(t("settings.codexDisconnected"));
-      setMsgType("success");
-      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
-    } catch (err) {
-      setMsg(err instanceof Error ? err.message : t("settings.savingError"));
-      setMsgType("error");
-    } finally {
-      setDisconnecting(false);
-    }
-  }
-
-  const status = settings?.codexStatus;
-  const isConnected = status === "connected";
-
-  return (
-    <div data-testid="ai-provider-config-codex" className="space-y-4">
-      <div className="flex flex-wrap items-center gap-2 text-sm">
-        <span className="font-medium">
-          {t("settings.ai.codex.modelSlugLabel")}
-        </span>
-        {isConnected ? (
-          <Badge className="border-success/30 bg-success/15 text-success">
-            {t("settings.ai.codex.statusConnected")}
-          </Badge>
-        ) : status === "expired" ? (
-          <Badge className="border-warning/30 bg-warning/15 text-warning">
-            {t("settings.ai.codex.statusExpired")}
-          </Badge>
-        ) : (
-          <Badge variant="outline">
-            {t("settings.ai.codex.statusDisconnected")}
-          </Badge>
-        )}
-      </div>
-      <p className="text-muted-foreground text-xs">
-        {t("settings.ai.codex.modelSlugBody")}
-      </p>
-      {settings?.lastInsightAt && (
-        <p className="text-muted-foreground text-xs">
-          {t("settings.ai.codex.lastInsight", {
-            when: formatDateTime(settings.lastInsightAt),
-          })}
-        </p>
-      )}
-      {settings?.codexConnectedAt && isConnected && (
-        <p className="text-muted-foreground text-xs">
-          {t("settings.ai.connectedSince", {
-            when: formatDateTime(settings.codexConnectedAt),
-          })}
-        </p>
-      )}
-
-      {settings?.codexOauthConfigured === false ? (
-        <p className="text-muted-foreground text-xs italic">
-          {t("settings.ai.oauthNotConfigured")}
-        </p>
-      ) : isConnected ? (
-        <Button
-          variant="outline"
-          size="sm"
-          className="text-destructive shrink-0"
-          onClick={handleDisconnect}
-          disabled={disconnecting}
-        >
-          {disconnecting ? (
-            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-          ) : (
-            <Trash2 className="h-4 w-4" />
-          )}
-          {t("settings.ai.codex.disconnectButton")}
-        </Button>
-      ) : deviceCode ? (
-        <div className="border-primary bg-primary/5 space-y-3 rounded-lg border-l-4 p-4">
-          <p className="text-sm font-medium">
-            {t("settings.ai.deviceCodeHeading")}
-          </p>
-          <ol className="text-muted-foreground list-decimal space-y-2 pl-5 text-sm">
-            <li>
-              {t("settings.ai.deviceCodeStep1")}{" "}
-              <a
-                href={deviceCode.verificationUrl}
-                target="_blank"
-                rel="noopener noreferrer"
-                className="text-primary font-medium underline"
-              >
-                {deviceCode.verificationUrl}
-              </a>
-            </li>
-            <li>
-              {t("settings.ai.deviceCodeStep2")}
-              <div className="bg-card border-border mt-2 inline-flex items-center gap-2 rounded border px-3 py-2 font-mono text-lg tracking-widest">
-                {deviceCode.userCode}
-                <button
-                  type="button"
-                  onClick={() =>
-                    navigator.clipboard?.writeText(deviceCode.userCode)
-                  }
-                  className="text-muted-foreground hover:text-foreground text-xs underline"
-                >
-                  {t("settings.ai.deviceCodeCopy")}
-                </button>
-              </div>
-            </li>
-            <li>{t("settings.ai.deviceCodeStep3")}</li>
-          </ol>
-          <div className="flex items-center gap-3 text-xs">
-            {devicePolling && (
-              <span className="text-muted-foreground inline-flex items-center gap-1">
-                <Loader2 className="h-3 w-3 animate-spin motion-reduce:animate-none" />
-                {t("settings.ai.deviceCodeWaiting")}
-              </span>
-            )}
-            <button
-              type="button"
-              onClick={handleCancelDevice}
-              className="text-muted-foreground hover:text-foreground underline"
-            >
-              {t("settings.ai.deviceCodeCancel")}
-            </button>
-          </div>
-        </div>
-      ) : (
-        <Button
-          variant="outline"
-          onClick={handleConnect}
-          disabled={devicePolling}
-          className="w-full sm:w-auto"
-        >
-          {devicePolling ? (
-            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-          ) : (
-            <Sparkles className="h-4 w-4" />
-          )}
-          {t("settings.ai.codex.connectButton")}
-        </Button>
-      )}
-
-      {msg && (
-        <p
-          role="alert"
-          className={`text-sm ${msgType === "success" ? "text-success" : "text-destructive"}`}
-        >
-          {msg}
-        </p>
-      )}
-    </div>
-  );
-}
-
-/* ────────────────────────────────────────────────────────────────
- * OpenAI form — API key + model select + collapsed Base URL override.
- * Save mutation flips both `aiProvider` (for the legacy single-result
- * resolver) and `aiOpenaiKeyEncrypted` (the user's key) so an OPENAI
- * pick is visible to every code path that reads the row.
- * ──────────────────────────────────────────────────────────────── */
-
-function OpenAIProviderForm({
-  userProvider,
-}: {
-  userProvider: UserAIProvider | null | undefined;
-}) {
-  const { t } = useTranslations();
-  const queryClient = useQueryClient();
-
-  const [apiKey, setApiKey] = useState("");
-  const [modelChoice, setModelChoice] = useState<string>("");
-  const [customModel, setCustomModel] = useState("");
-  const [baseUrl, setBaseUrl] = useState("");
-  const [showAdvanced, setShowAdvanced] = useState(false);
-  const [msg, setMsg] = useState<string | null>(null);
-  const [ok, setOk] = useState(false);
-
-  const seededKey =
-    userProvider != null
-      ? `${userProvider.provider ?? ""}|${userProvider.model ?? ""}|${userProvider.baseUrl ?? ""}`
-      : null;
-  const [previousSeed, setPreviousSeed] = useState<string | null>(null);
-  if (seededKey && seededKey !== previousSeed) {
-    setPreviousSeed(seededKey);
-    if (userProvider?.provider === "OPENAI") {
-      const saved = userProvider.model ?? "";
-      if (
-        saved &&
-        (OPENAI_MODEL_PRESETS as readonly string[]).includes(saved)
-      ) {
-        setModelChoice(saved);
-        setCustomModel("");
-      } else if (saved) {
-        setModelChoice(CUSTOM_MODEL_SENTINEL);
-        setCustomModel(saved);
-      }
-      setBaseUrl(userProvider.baseUrl ?? "");
-    }
-  }
-
-  const effectiveModel =
-    modelChoice === CUSTOM_MODEL_SENTINEL
-      ? customModel.trim()
-      : modelChoice.trim();
-
-  const saveMutation = useMutation({
-    mutationFn: async () => {
-      const body: Record<string, unknown> = {
-        provider: uiToLegacyProviderEnum("openai"),
-        model: effectiveModel || null,
-        baseUrl: baseUrl.trim() || null,
-      };
-      if (apiKey.trim()) body.openaiKey = apiKey.trim();
-      const res = await fetch("/api/user/ai-provider", {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("settings.ai.saveFailed"));
-    },
-    onSuccess: () => {
-      setOk(true);
-      setMsg(t("settings.ai.saved"));
-      setApiKey("");
-      queryClient.invalidateQueries({ queryKey: queryKeys.userAiProvider() });
-      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
-    },
-    onError: (e) => {
-      setOk(false);
-      setMsg(e instanceof Error ? e.message : t("settings.ai.errorGeneric"));
-    },
-  });
-
-  return (
-    <div data-testid="ai-provider-config-openai" className="space-y-4">
-      <div>
-        <Label htmlFor="ai-openai-key">
-          {t("settings.ai.openai.apiKey")}
-          {userProvider?.hasOpenaiKey && (
-            <span className="text-muted-foreground ml-2 text-xs">
-              {t("settings.ai.savedPreview", {
-                preview: userProvider.openaiKeyPreview ?? "",
-              })}
-            </span>
-          )}
-        </Label>
-        <PasswordInput
-          id="ai-openai-key"
-          data-testid="ai-openai-api-key"
-          value={apiKey}
-          onChange={(e) => setApiKey(e.target.value)}
-          placeholder={t("settings.ai.openai.apiKeyPlaceholder")}
-          className="mt-1"
-        />
-      </div>
-
-      <div>
-        <Label htmlFor="ai-openai-model">
-          {t("settings.ai.openai.modelSelect")}
-        </Label>
-        <NativeSelect
-          id="ai-openai-model"
-          data-testid="ai-openai-model"
-          value={modelChoice}
-          onChange={(e) => setModelChoice(e.target.value)}
-          className="mt-1"
-        >
-          <option value="">{t("settings.ai.modelOptionDefault")}</option>
-          {OPENAI_MODEL_PRESETS.map((m) => (
-            <option key={m} value={m}>
-              {m}
-            </option>
-          ))}
-          <option value={CUSTOM_MODEL_SENTINEL}>
-            {t("settings.ai.openai.modelOptionCustom")}
-          </option>
-        </NativeSelect>
-      </div>
-
-      {modelChoice === CUSTOM_MODEL_SENTINEL && (
-        <div>
-          <Label htmlFor="ai-openai-model-custom">
-            {t("settings.ai.openai.modelCustomLabel")}
-          </Label>
-          <Input
-            id="ai-openai-model-custom"
-            value={customModel}
-            onChange={(e) => setCustomModel(e.target.value)}
-            placeholder={t("settings.ai.openai.modelCustomPlaceholder")}
-            className="mt-1"
-          />
-        </div>
-      )}
-
-      <div>
-        <button
-          type="button"
-          onClick={() => setShowAdvanced((v) => !v)}
-          className="text-muted-foreground hover:text-foreground text-xs underline"
-        >
-          {showAdvanced
-            ? t("settings.ai.openai.hideAdvanced")
-            : t("settings.ai.openai.showAdvanced")}
-        </button>
-        {showAdvanced && (
-          <div className="mt-2 space-y-1">
-            <Label htmlFor="ai-openai-base-url">
-              {t("settings.ai.openai.baseUrlLabel")}
-            </Label>
-            <Input
-              id="ai-openai-base-url"
-              value={baseUrl}
-              onChange={(e) => setBaseUrl(e.target.value)}
-              placeholder={t("settings.ai.openai.baseUrlPlaceholder")}
-            />
-            <p className="text-muted-foreground text-xs">
-              {t("settings.ai.openai.baseUrlHelp")}
-            </p>
-          </div>
-        )}
-      </div>
-
-      <div className="flex flex-wrap gap-2">
-        <Button
-          size="sm"
-          onClick={() => saveMutation.mutate()}
-          disabled={saveMutation.isPending}
-        >
-          {saveMutation.isPending ? (
-            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-          ) : (
-            <Save className="h-4 w-4" />
-          )}
-          {t("settings.ai.saveCta")}
-        </Button>
-      </div>
-
-      {msg && (
-        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
-          {msg}
-        </p>
-      )}
-    </div>
-  );
-}
-
-/* ────────────────────────────────────────────────────────────────
- * Anthropic form — API key + model dropdown.
- * ──────────────────────────────────────────────────────────────── */
-
-function AnthropicProviderForm({
-  userProvider,
-}: {
-  userProvider: UserAIProvider | null | undefined;
-}) {
-  const { t } = useTranslations();
-  const queryClient = useQueryClient();
-
-  const [apiKey, setApiKey] = useState("");
-  const [modelChoice, setModelChoice] = useState<string>("");
-  const [customModel, setCustomModel] = useState("");
-  const [msg, setMsg] = useState<string | null>(null);
-  const [ok, setOk] = useState(false);
-
-  const seededKey =
-    userProvider != null
-      ? `${userProvider.provider ?? ""}|${userProvider.model ?? ""}`
-      : null;
-  const [previousSeed, setPreviousSeed] = useState<string | null>(null);
-  if (seededKey && seededKey !== previousSeed) {
-    setPreviousSeed(seededKey);
-    if (userProvider?.provider === "ANTHROPIC") {
-      const saved = userProvider.model ?? "";
-      if (
-        saved &&
-        (ANTHROPIC_MODEL_PRESETS as readonly string[]).includes(saved)
-      ) {
-        setModelChoice(saved);
-        setCustomModel("");
-      } else if (saved) {
-        setModelChoice(CUSTOM_MODEL_SENTINEL);
-        setCustomModel(saved);
-      }
-    }
-  }
-
-  const effectiveModel =
-    modelChoice === CUSTOM_MODEL_SENTINEL
-      ? customModel.trim()
-      : modelChoice.trim();
-
-  const saveMutation = useMutation({
-    mutationFn: async () => {
-      const body: Record<string, unknown> = {
-        provider: uiToLegacyProviderEnum("anthropic"),
-        model: effectiveModel || null,
-      };
-      if (apiKey.trim()) body.anthropicKey = apiKey.trim();
-      const res = await fetch("/api/user/ai-provider", {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("settings.ai.saveFailed"));
-    },
-    onSuccess: () => {
-      setOk(true);
-      setMsg(t("settings.ai.saved"));
-      setApiKey("");
-      queryClient.invalidateQueries({ queryKey: queryKeys.userAiProvider() });
-      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
-    },
-    onError: (e) => {
-      setOk(false);
-      setMsg(e instanceof Error ? e.message : t("settings.ai.errorGeneric"));
-    },
-  });
-
-  return (
-    <div data-testid="ai-provider-config-anthropic" className="space-y-4">
-      <div>
-        <Label htmlFor="ai-anthropic-key">
-          {t("settings.ai.anthropicKeyLabel")}
-          {userProvider?.hasAnthropicKey && (
-            <span className="text-muted-foreground ml-2 text-xs">
-              {t("settings.ai.savedPreview", {
-                preview: userProvider.anthropicKeyPreview ?? "",
-              })}
-            </span>
-          )}
-        </Label>
-        <PasswordInput
-          id="ai-anthropic-key"
-          value={apiKey}
-          onChange={(e) => setApiKey(e.target.value)}
-          placeholder="sk-ant-…"
-          className="mt-1"
-        />
-      </div>
-
-      <div>
-        <Label htmlFor="ai-anthropic-model">
-          {t("settings.ai.modelLabel")}
-        </Label>
-        <NativeSelect
-          id="ai-anthropic-model"
-          value={modelChoice}
-          onChange={(e) => setModelChoice(e.target.value)}
-          className="mt-1"
-        >
-          <option value="">{t("settings.ai.modelOptionDefault")}</option>
-          {ANTHROPIC_MODEL_PRESETS.map((m) => (
-            <option key={m} value={m}>
-              {m}
-            </option>
-          ))}
-          <option value={CUSTOM_MODEL_SENTINEL}>
-            {t("settings.ai.modelOptionCustom")}
-          </option>
-        </NativeSelect>
-      </div>
-
-      {modelChoice === CUSTOM_MODEL_SENTINEL && (
-        <div>
-          <Label htmlFor="ai-anthropic-model-custom">
-            {t("settings.ai.customModelLabel")}
-          </Label>
-          <Input
-            id="ai-anthropic-model-custom"
-            value={customModel}
-            onChange={(e) => setCustomModel(e.target.value)}
-            placeholder="claude-3-5-sonnet-latest"
-            className="mt-1"
-          />
-        </div>
-      )}
-
-      <div>
-        <Button
-          size="sm"
-          onClick={() => saveMutation.mutate()}
-          disabled={saveMutation.isPending}
-        >
-          {saveMutation.isPending ? (
-            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-          ) : (
-            <Save className="h-4 w-4" />
-          )}
-          {t("settings.ai.saveCta")}
-        </Button>
-      </div>
-
-      {msg && (
-        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
-          {msg}
-        </p>
-      )}
-    </div>
-  );
-}
-
-/* ────────────────────────────────────────────────────────────────
- * Local (OpenAI-compatible) form — base URL + optional key + model.
- * ──────────────────────────────────────────────────────────────── */
-
-function LocalProviderForm({
-  userProvider,
-}: {
-  userProvider: UserAIProvider | null | undefined;
-}) {
-  const { t } = useTranslations();
-  const queryClient = useQueryClient();
-
-  const [baseUrl, setBaseUrl] = useState("");
-  const [apiKey, setApiKey] = useState("");
-  const [modelChoice, setModelChoice] = useState<string>("");
-  const [customModel, setCustomModel] = useState("");
-  const [msg, setMsg] = useState<string | null>(null);
-  const [ok, setOk] = useState(false);
-
-  const seededKey =
-    userProvider != null
-      ? `${userProvider.provider ?? ""}|${userProvider.model ?? ""}|${userProvider.baseUrl ?? ""}`
-      : null;
-  const [previousSeed, setPreviousSeed] = useState<string | null>(null);
-  if (seededKey && seededKey !== previousSeed) {
-    setPreviousSeed(seededKey);
-    if (userProvider?.provider === "LOCAL") {
-      setBaseUrl(userProvider.baseUrl ?? "");
-      const saved = userProvider.model ?? "";
-      if (saved && (LOCAL_MODEL_PRESETS as readonly string[]).includes(saved)) {
-        setModelChoice(saved);
-        setCustomModel("");
-      } else if (saved) {
-        setModelChoice(CUSTOM_MODEL_SENTINEL);
-        setCustomModel(saved);
-      }
-    }
-  }
-
-  const effectiveModel =
-    modelChoice === CUSTOM_MODEL_SENTINEL
-      ? customModel.trim()
-      : modelChoice.trim();
-
-  const saveMutation = useMutation({
-    mutationFn: async () => {
-      const body: Record<string, unknown> = {
-        provider: uiToLegacyProviderEnum("local"),
-        baseUrl: baseUrl.trim() || null,
-        model: effectiveModel || null,
-      };
-      if (apiKey.trim()) body.localKey = apiKey.trim();
-      const res = await fetch("/api/user/ai-provider", {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      const json = await res.json();
-      if (!res.ok) throw new Error(json.error || t("settings.ai.saveFailed"));
-    },
-    onSuccess: () => {
-      setOk(true);
-      setMsg(t("settings.ai.saved"));
-      setApiKey("");
-      queryClient.invalidateQueries({ queryKey: queryKeys.userAiProvider() });
-      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
-    },
-    onError: (e) => {
-      setOk(false);
-      setMsg(e instanceof Error ? e.message : t("settings.ai.errorGeneric"));
-    },
-  });
-
-  return (
-    <div data-testid="ai-provider-config-local" className="space-y-4">
-      <div>
-        <Label htmlFor="ai-local-base-url">
-          {t("settings.ai.baseUrlLabel")}
-        </Label>
-        <Input
-          id="ai-local-base-url"
-          value={baseUrl}
-          onChange={(e) => setBaseUrl(e.target.value)}
-          placeholder="http://localhost:11434/v1"
-          className="mt-1"
-        />
-      </div>
-      <div>
-        <Label htmlFor="ai-local-key">{t("settings.ai.localKeyLabel")}</Label>
-        <PasswordInput
-          id="ai-local-key"
-          value={apiKey}
-          onChange={(e) => setApiKey(e.target.value)}
-          placeholder={
-            userProvider?.hasLocalKey ? t("settings.ai.savedShort") : ""
-          }
-          className="mt-1"
-        />
-      </div>
-      <div>
-        <Label htmlFor="ai-local-model">{t("settings.ai.modelLabel")}</Label>
-        <NativeSelect
-          id="ai-local-model"
-          value={modelChoice}
-          onChange={(e) => setModelChoice(e.target.value)}
-          className="mt-1"
-        >
-          <option value="">{t("settings.ai.modelOptionDefault")}</option>
-          {LOCAL_MODEL_PRESETS.map((m) => (
-            <option key={m} value={m}>
-              {m}
-            </option>
-          ))}
-          <option value={CUSTOM_MODEL_SENTINEL}>
-            {t("settings.ai.modelOptionCustom")}
-          </option>
-        </NativeSelect>
-      </div>
-      {modelChoice === CUSTOM_MODEL_SENTINEL && (
-        <div>
-          <Label htmlFor="ai-local-model-custom">
-            {t("settings.ai.customModelLabel")}
-          </Label>
-          <Input
-            id="ai-local-model-custom"
-            value={customModel}
-            onChange={(e) => setCustomModel(e.target.value)}
-            placeholder="llama3:8b"
-            className="mt-1"
-          />
-        </div>
-      )}
-
-      <div>
-        <Button
-          size="sm"
-          onClick={() => saveMutation.mutate()}
-          disabled={saveMutation.isPending}
-        >
-          {saveMutation.isPending ? (
-            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-          ) : (
-            <Save className="h-4 w-4" />
-          )}
-          {t("settings.ai.saveCta")}
-        </Button>
-      </div>
-
-      {msg && (
-        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
-          {msg}
-        </p>
-      )}
-    </div>
-  );
-}
-
-/* ────────────────────────────────────────────────────────────────
- * Admin OpenAI form — read-only "the operator has set this up".
- * ──────────────────────────────────────────────────────────────── */
-
-function AdminOpenAIProviderForm({
-  hasAdminKey,
-}: {
-  hasAdminKey: boolean | undefined;
-}) {
-  const { t } = useTranslations();
-  return (
-    <div data-testid="ai-provider-config-admin-openai" className="space-y-2">
-      <p className="text-sm font-medium">
-        {t("settings.ai.adminOpenai.title")}
-      </p>
-      <p className="text-muted-foreground text-xs">
-        {hasAdminKey
-          ? t("settings.ai.adminOpenai.body")
-          : t("settings.ai.adminOpenai.notConfigured")}
-      </p>
-    </div>
-  );
-}
-
-/* ────────────────────────────────────────────────────────────────
- * Fallback chain card — reorder via arrows, toggle, remove, add,
- * reset. Uses no new dependency (dnd-kit isn't in package.json).
- * ──────────────────────────────────────────────────────────────── */
-
-function FallbackChainCard({
-  chain,
-  selected,
-  onSelect,
-}: {
-  chain: {
-    providerType: ProviderType;
-    enabled: boolean;
-    available: boolean;
-  }[];
-  selected: ProviderType;
-  onSelect: (next: ProviderType) => void;
-}) {
-  const { t } = useTranslations();
-  const queryClient = useQueryClient();
-
-  // Local working copy. Server-confirmed values arrive via `chain`
-  // prop; we keep our own state so the user can shuffle multiple rows
-  // before clicking "Save chain order".
-  // v1.4.16 phase D reconcile (code-review H2) — `enabled` from the
-  // wire is now the canonical state. The GET endpoint surfaces the
-  // raw persisted chain so a disabled entry survives the round-trip.
-  const seededKey = chain
-    .map((c) => `${c.providerType}:${c.enabled ? 1 : 0}`)
-    .join(",");
-  const [seeded, setSeeded] = useState<string | null>(null);
-  const [entries, setEntries] = useState<ChainEntry[]>(() =>
-    chain.map((c) => ({ providerType: c.providerType, enabled: c.enabled })),
-  );
-  if (seededKey !== seeded) {
-    setSeeded(seededKey);
-    setEntries(
-      chain.map((c) => ({
-        providerType: c.providerType,
-        enabled: c.enabled,
-      })),
-    );
-  }
-
-  const [msg, setMsg] = useState<string | null>(null);
-  const [ok, setOk] = useState(false);
-
-  const saveMutation = useMutation({
-    mutationFn: async (next: ChainEntry[]) => {
-      const body = {
-        chain: next.map((entry, idx) => ({
-          providerType: entry.providerType,
-          priority: idx + 1,
-          enabled: entry.enabled,
-        })),
-      };
-      const res = await fetch("/api/insights/provider-chain", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      const json = await res.json();
-      if (!res.ok) {
-        throw new Error(
-          json.error || t("settings.ai.providerChain.saveFailed"),
-        );
-      }
-    },
-    onSuccess: () => {
-      setOk(true);
-      setMsg(t("settings.ai.providerChain.saved"));
-      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
-    },
-    onError: (e) => {
-      setOk(false);
-      setMsg(
-        e instanceof Error
-          ? e.message
-          : t("settings.ai.providerChain.saveFailed"),
-      );
-    },
-  });
-
-  function move(idx: number, delta: -1 | 1) {
-    setEntries((prev) => {
-      const next = [...prev];
-      const target = idx + delta;
-      if (target < 0 || target >= next.length) return prev;
-      [next[idx], next[target]] = [next[target], next[idx]];
-      return next;
-    });
-  }
-
-  function toggle(idx: number) {
-    setEntries((prev) => {
-      const next = [...prev];
-      next[idx] = { ...next[idx], enabled: !next[idx].enabled };
-      return next;
-    });
-  }
-
-  function remove(idx: number) {
-    setEntries((prev) => prev.filter((_, i) => i !== idx));
-  }
-
-  const present = useMemo(
-    () => new Set(entries.map((e) => e.providerType)),
-    [entries],
-  );
-  const addable = PROVIDER_TYPES.filter((p) => !present.has(p));
-
-  function add(p: ProviderType) {
-    setEntries((prev) => [...prev, { providerType: p, enabled: true }]);
-  }
-
-  function resetToDefaults() {
-    setEntries(DEFAULT_CHAIN.map((d) => ({ ...d })));
-  }
-
-  return (
-    <div
-      data-testid="ai-fallback-chain"
-      className="bg-muted/50 space-y-3 rounded-lg p-4"
-    >
-      <div>
-        <p className="text-sm font-medium">
-          {t("settings.ai.providerChain.title")}
-        </p>
-        <p className="text-muted-foreground text-xs">
-          {t("settings.ai.providerChain.description")}
-        </p>
-      </div>
-
-      <ul className="space-y-2">
-        {entries.map((entry, idx) => (
-          <li
-            key={entry.providerType}
-            data-chain-row={entry.providerType}
-            className={`bg-card border-border flex flex-wrap items-center gap-2 rounded-md border p-2 ${
-              entry.providerType === selected
-                ? "border-primary/40 ring-primary/30 ring-1"
-                : ""
-            }`}
-          >
-            <span className="text-muted-foreground w-5 text-center text-xs tabular-nums">
-              {idx + 1}.
-            </span>
-            <button
-              type="button"
-              onClick={() => onSelect(entry.providerType)}
-              className="flex-1 text-left text-sm font-medium hover:underline"
-            >
-              {t(`settings.ai.providerChain.types.${entry.providerType}`)}
-            </button>
-            <Switch
-              checked={entry.enabled}
-              onCheckedChange={() => toggle(idx)}
-              aria-label={t(
-                `settings.ai.providerChain.types.${entry.providerType}`,
-              )}
-            />
-            <Button
-              type="button"
-              size="sm"
-              variant="outline"
-              aria-label={t("settings.ai.providerChain.moveUp")}
-              disabled={idx === 0}
-              onClick={() => move(idx, -1)}
-            >
-              <ArrowUp className="h-4 w-4" />
-            </Button>
-            <Button
-              type="button"
-              size="sm"
-              variant="outline"
-              aria-label={t("settings.ai.providerChain.moveDown")}
-              disabled={idx === entries.length - 1}
-              onClick={() => move(idx, 1)}
-            >
-              <ArrowDown className="h-4 w-4" />
-            </Button>
-            <Button
-              type="button"
-              size="sm"
-              variant="outline"
-              aria-label={t("settings.ai.providerChain.removeFromChain")}
-              className="text-destructive"
-              onClick={() => remove(idx)}
-              disabled={entries.length <= 1}
-            >
-              <X className="h-4 w-4" />
-            </Button>
-          </li>
-        ))}
-      </ul>
-
-      <div className="flex flex-wrap items-center gap-2">
-        {addable.length > 0 ? (
-          <AddProviderControl addable={addable} onAdd={add} />
-        ) : (
-          <p className="text-muted-foreground text-xs italic">
-            {t("settings.ai.providerChain.addNoneAvailable")}
-          </p>
-        )}
-        <Button
-          size="sm"
-          onClick={() => saveMutation.mutate(entries)}
-          disabled={saveMutation.isPending || entries.length === 0}
-          data-testid="ai-fallback-chain-save"
-        >
-          {saveMutation.isPending ? (
-            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-          ) : (
-            <Save className="h-4 w-4" />
-          )}
-          {t("settings.ai.providerChain.saveOrder")}
-        </Button>
-        <AlertDialog>
-          <AlertDialogTrigger asChild>
-            <Button size="sm" variant="outline">
-              <RotateCcw className="h-4 w-4" />
-              {t("settings.ai.providerChain.resetDefaults")}
-            </Button>
-          </AlertDialogTrigger>
-          <AlertDialogContent>
-            <AlertDialogHeader>
-              <AlertDialogTitle>
-                {t("settings.ai.providerChain.resetConfirmTitle")}
-              </AlertDialogTitle>
-              <AlertDialogDescription>
-                {t("settings.ai.providerChain.resetConfirmBody")}
-              </AlertDialogDescription>
-            </AlertDialogHeader>
-            <AlertDialogFooter>
-              <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
-              <AlertDialogAction onClick={resetToDefaults}>
-                {t("settings.ai.providerChain.resetDefaults")}
-              </AlertDialogAction>
-            </AlertDialogFooter>
-          </AlertDialogContent>
-        </AlertDialog>
-      </div>
-
-      {msg && (
-        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
-          {msg}
-        </p>
-      )}
-    </div>
-  );
-}
-
-function AddProviderControl({
-  addable,
-  onAdd,
-}: {
-  addable: readonly ProviderType[];
-  onAdd: (p: ProviderType) => void;
-}) {
-  const { t } = useTranslations();
-  const [picked, setPicked] = useState<string>(addable[0] ?? "");
-
-  return (
-    <div className="flex items-center gap-2">
-      <NativeSelect
-        aria-label={t("settings.ai.providerChain.addProvider")}
-        value={picked}
-        onChange={(e) => setPicked(e.target.value)}
-        className="w-auto"
-      >
-        {addable.map((p) => (
-          <option key={p} value={p}>
-            {t(`settings.ai.providerChain.types.${p}`)}
-          </option>
-        ))}
-      </NativeSelect>
-      <Button
-        type="button"
-        size="sm"
-        variant="outline"
-        onClick={() => {
-          if (isProviderType(picked)) onAdd(picked);
-        }}
-      >
-        <PlusCircle className="h-4 w-4" />
-        {t("settings.ai.providerChain.addProvider")}
-      </Button>
-    </div>
-  );
-}
-
-/* ────────────────────────────────────────────────────────────────
- * Runtime actions — Test active provider, regenerate insights, raw-mode toggle.
- * ──────────────────────────────────────────────────────────────── */
-
-function RuntimeActionsRow({
-  provider,
-  userProvider,
-  canRegenerate,
-  privacyMode,
-  lastInsightAt,
-  onRegenerated,
-  onPrivacyChanged,
-}: {
-  provider: ProviderType;
-  userProvider: UserAIProvider | null | undefined;
-  canRegenerate: boolean;
-  privacyMode: string;
-  lastInsightAt: string | null;
-  onRegenerated: () => void;
-  onPrivacyChanged: () => void;
-}) {
-  const { t } = useTranslations();
-
-  const [testing, setTesting] = useState(false);
-  const [testMsg, setTestMsg] = useState<string | null>(null);
-  const [testOk, setTestOk] = useState(false);
-  const [regen, setRegen] = useState(false);
-  const [regenMsg, setRegenMsg] = useState<string | null>(null);
-  const [regenOk, setRegenOk] = useState(false);
-
-  async function runTest() {
-    setTesting(true);
-    setTestMsg(null);
-    try {
-      const res = await fetch("/api/ai/test", { method: "POST" });
-      // Guard against a non-JSON body. A reverse proxy / Cloudflare can
-      // rewrite an origin error to its own HTML page; parsing that as JSON
-      // throws `Unexpected token '<'` (Safari: "did not match the
-      // expected pattern"). Show a clean message instead of leaking that.
-      const contentType = res.headers.get("content-type") ?? "";
-      if (!contentType.includes("application/json")) {
-        setTestOk(false);
-        setTestMsg(t("settings.ai.testUnexpectedResponse"));
-        return;
-      }
-      let json: {
-        data?: {
-          ok?: boolean;
-          providerType?: string;
-          model?: string;
-          reasonCode?: string;
-          reason?: string;
-        } | null;
-        error?: string | null;
-      };
-      try {
-        json = await res.json();
-      } catch {
-        setTestOk(false);
-        setTestMsg(t("settings.ai.testUnexpectedResponse"));
-        return;
-      }
-      // 4xx config errors still arrive via the error envelope.
-      if (!res.ok) {
-        setTestOk(false);
-        setTestMsg(
-          t("settings.ai.testFailedShort", {
-            message: json.error ?? `HTTP ${res.status}`,
-          }),
-        );
-        return;
-      }
-      // Provider-call failures now arrive as 200 + { ok:false, reasonCode }
-      // so the body is never rewritten by a proxy. Map the stable code to a
-      // localised string; fall back to the server's plain `reason` for any
-      // unmapped / legacy code, then to a generic message.
-      if (json.data && json.data.ok === false) {
-        setTestOk(false);
-        setTestMsg(
-          localiseTestReason(t, json.data.reasonCode, json.data.reason) ??
-            t("settings.ai.testFailedShort", { message: `HTTP ${res.status}` }),
-        );
-        return;
-      }
-      setTestOk(true);
-      setTestMsg(
-        t("settings.ai.testSuccess", {
-          provider: json.data?.providerType ?? "",
-          model: json.data?.model ?? "",
-        }),
-      );
-    } catch (e) {
-      setTestOk(false);
-      setTestMsg(
-        t("settings.ai.testFailedShort", {
-          message: e instanceof Error ? e.message : "fetch error",
-        }),
-      );
-    } finally {
-      setTesting(false);
-    }
-  }
-
-  async function regenerate() {
-    setRegen(true);
-    setRegenMsg(null);
-    try {
-      const res = await fetch("/api/insights/generate", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ force: true }),
-      });
-      // Same defensive guard as the connection test: a proxy can rewrite
-      // a 5xx (e.g. all-providers-failed) to an HTML page, which would
-      // crash `res.json()` with `Unexpected token '<'`.
-      const contentType = res.headers.get("content-type") ?? "";
-      if (!contentType.includes("application/json")) {
-        setRegenOk(false);
-        setRegenMsg(
-          res.status === 429
-            ? t("settings.regenerateRateLimit")
-            : t("settings.ai.testUnexpectedResponse"),
-        );
-        return;
-      }
-      let json: { error?: string | null };
-      try {
-        json = await res.json();
-      } catch {
-        setRegenOk(false);
-        setRegenMsg(t("settings.ai.testUnexpectedResponse"));
-        return;
-      }
-      if (!res.ok) {
-        setRegenOk(false);
-        setRegenMsg(
-          res.status === 429
-            ? t("settings.regenerateRateLimit")
-            : json.error || t("settings.savingError"),
-        );
-        return;
-      }
-      setRegenOk(true);
-      setRegenMsg(t("settings.regenerateSuccess"));
-      onRegenerated();
-    } catch {
-      setRegenOk(false);
-      setRegenMsg(t("settings.savingError"));
-    } finally {
-      setRegen(false);
-    }
-  }
-
-  async function togglePrivacy() {
-    const next = privacyMode === "raw" ? "aggregated" : "raw";
-    // Privacy mode is a sensitive control: only reflect the new mode
-    // once the server confirms it. A swallowed 4xx/5xx would leave the
-    // UI showing a setting the server never accepted.
-    try {
-      const res = await fetch("/api/insights/settings", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ privacyMode: next }),
-      });
-      if (!res.ok) throw new Error("request failed");
-      onPrivacyChanged();
-    } catch {
-      toast.error(t("settings.savingError"));
-    }
-  }
-
-  const lastInsightLine = lastInsightAt
-    ? `${t("settings.lastGeneratedAt")}: ${formatDateTime(lastInsightAt)}`
-    : null;
-
-  // Reserved for a future iteration that gates the Test button per
-  // provider (e.g. disable when admin-openai is selected and no admin
-  // key is present). For v1.4.16 the API decides.
-  void provider;
-  void userProvider;
-
-  return (
-    <div className="space-y-3">
-      <div className="flex flex-wrap items-center gap-2">
-        <Button
-          size="sm"
-          variant="outline"
-          onClick={runTest}
-          disabled={testing}
-          data-testid="ai-test-active-provider"
-        >
-          {testing ? (
-            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-          ) : (
-            <Sparkles className="h-4 w-4" />
-          )}
-          {t("settings.ai.testProvider")}
-        </Button>
-        {canRegenerate && (
-          <Button
-            size="sm"
-            variant="outline"
-            onClick={regenerate}
-            disabled={regen}
-          >
-            {regen ? (
-              <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
-            ) : (
-              <RefreshCw className="h-4 w-4" />
-            )}
-            {t("settings.regenerateInsights")}
-          </Button>
-        )}
-        {lastInsightLine && (
-          <span className="text-muted-foreground text-xs">
-            {lastInsightLine}
-          </span>
-        )}
-      </div>
-
-      {canRegenerate && (
-        <div className="bg-muted/50 rounded-lg p-3">
-          <div className="flex items-center justify-between gap-4">
-            <div className="pr-2">
-              <p className="text-sm font-medium">{t("settings.rawData")}</p>
-              <p className="text-muted-foreground text-xs">
-                {privacyMode === "raw"
-                  ? t("settings.rawDataOnDescription")
-                  : t("settings.rawDataOffDescription")}
-              </p>
-            </div>
-            <Switch
-              checked={privacyMode === "raw"}
-              onCheckedChange={togglePrivacy}
-            />
-          </div>
-          {privacyMode === "raw" && (
-            <div className="bg-warning/15 text-warning mt-2 rounded-lg p-2 text-xs">
-              {t("settings.rawDataWarning")}
-            </div>
-          )}
-        </div>
-      )}
-
-      {testMsg && (
-        <p
-          className={`text-xs ${testOk ? "text-success" : "text-destructive"}`}
-        >
-          {testMsg}
-        </p>
-      )}
-      {regenMsg && (
-        <p
-          className={`text-xs ${regenOk ? "text-success" : "text-destructive"}`}
-        >
-          {regenMsg}
-        </p>
-      )}
-    </div>
-  );
-}
diff --git a/src/components/settings/ai/admin-openai-provider-form.tsx b/src/components/settings/ai/admin-openai-provider-form.tsx
new file mode 100644
index 000000000..38229d5d4
--- /dev/null
+++ b/src/components/settings/ai/admin-openai-provider-form.tsx
@@ -0,0 +1,27 @@
+"use client";
+
+/* ────────────────────────────────────────────────────────────────
+ * Admin OpenAI form — read-only "the operator has set this up".
+ * ──────────────────────────────────────────────────────────────── */
+
+import { useTranslations } from "@/lib/i18n/context";
+
+export function AdminOpenAIProviderForm({
+  hasAdminKey,
+}: {
+  hasAdminKey: boolean | undefined;
+}) {
+  const { t } = useTranslations();
+  return (
+    <div data-testid="ai-provider-config-admin-openai" className="space-y-2">
+      <p className="text-sm font-medium">
+        {t("settings.ai.adminOpenai.title")}
+      </p>
+      <p className="text-muted-foreground text-xs">
+        {hasAdminKey
+          ? t("settings.ai.adminOpenai.body")
+          : t("settings.ai.adminOpenai.notConfigured")}
+      </p>
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/ai-insights-card.tsx b/src/components/settings/ai/ai-insights-card.tsx
new file mode 100644
index 000000000..615b7578c
--- /dev/null
+++ b/src/components/settings/ai/ai-insights-card.tsx
@@ -0,0 +1,311 @@
+"use client";
+
+/**
+ * The single dropdown-driven configuration card. Replaces the
+ * v1.4.15-vintage two-card layout (Codex connect at the top, personal
+ * provider form at the bottom) per the maintainer's
+ * `feedback_settings_no_split.md`: one provider Select, one matching
+ * form below, one fallback-chain card at the bottom.
+ *
+ * The active-provider Select is URL-synced via `?provider=…` so deep
+ * links to a specific config form work, the SSR test can drive the
+ * branch deterministically, and a refresh keeps the user on the form
+ * they were editing.
+ */
+
+import { useState } from "react";
+import { usePathname, useRouter, useSearchParams } from "next/navigation";
+import { useQuery, useQueryClient } from "@tanstack/react-query";
+import { Sparkles } from "lucide-react";
+
+import { Badge } from "@/components/ui/badge";
+import { Label } from "@/components/ui/label";
+import { NativeSelect } from "@/components/ui/native-select";
+import { SettingsCardHeader } from "@/components/settings/_card-header";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
+import { formatDateTime } from "@/lib/format";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+
+import { AdminOpenAIProviderForm } from "./admin-openai-provider-form";
+import { AnthropicProviderForm } from "./anthropic-provider-form";
+import { CodexProviderForm } from "./codex-provider-form";
+import { FallbackChainCard } from "./fallback-chain-card";
+import { LocalProviderForm } from "./local-provider-form";
+import { OpenAIProviderForm } from "./openai-provider-form";
+import { RuntimeActionsRow } from "./runtime-actions-row";
+import {
+  PROVIDER_TYPES,
+  isProviderType,
+  type InsightsSettings,
+  type ProviderChainData,
+  type ProviderType,
+  type UserAIProvider,
+} from "./shared";
+
+export function AiInsightsCard({
+  isAuthenticated,
+}: {
+  isAuthenticated: boolean;
+}) {
+  const { t } = useTranslations();
+  const queryClient = useQueryClient();
+  const router = useRouter();
+  const pathname = usePathname();
+  const searchParams = useSearchParams();
+
+  const { data: insightsSettings } = useQuery({
+    queryKey: queryKeys.insightsSettings(),
+    queryFn: async () => {
+      const res = await apiFetchRaw("/api/insights/settings");
+      if (!res.ok) return null;
+      const json = await res.json();
+      return json.data as InsightsSettings;
+    },
+    enabled: isAuthenticated,
+  });
+
+  const { data: userProvider } = useQuery({
+    queryKey: queryKeys.userAiProvider(),
+    queryFn: async () => {
+      const res = await apiFetchRaw("/api/user/ai-provider");
+      if (!res.ok) return null;
+      const json = await res.json();
+      return json.data as UserAIProvider;
+    },
+    enabled: isAuthenticated,
+  });
+
+  const { data: chainData } = useQuery({
+    queryKey: queryKeys.insightsProviderChain(),
+    queryFn: async () => {
+      const res = await apiFetchRaw("/api/insights/provider-chain");
+      if (!res.ok) return null;
+      const json = await res.json();
+      return json.data as ProviderChainData;
+    },
+    enabled: isAuthenticated,
+  });
+
+  // The Select is URL-driven so the SSR test can pick the branch and
+  // a deep link works. Default = `?provider=…` query param when the
+  // user navigated here intentionally, else the chain's active entry,
+  // else "codex". The seed-on-data-arrival pattern below avoids
+  // setState-in-effect (lint rule `react-hooks/set-state-in-effect`)
+  // by reading the resolved value at render time and consulting a
+  // `seededFor` marker so we only re-seed when the relevant inputs
+  // actually changed.
+  const queryProvider = searchParams?.get("provider") ?? null;
+  const [selectedProvider, setSelectedProvider] = useState<ProviderType>(() =>
+    isProviderType(queryProvider) ? queryProvider : "codex",
+  );
+  const seedKey = `${queryProvider ?? ""}|${chainData?.activeProvider ?? ""}`;
+  const [seededFor, setSeededFor] = useState<string>(seedKey);
+  if (seedKey !== seededFor) {
+    setSeededFor(seedKey);
+    if (isProviderType(queryProvider)) {
+      setSelectedProvider(queryProvider);
+    } else if (chainData?.activeProvider) {
+      setSelectedProvider(chainData.activeProvider);
+    }
+  }
+
+  function pickProvider(next: ProviderType) {
+    setSelectedProvider(next);
+    if (typeof window === "undefined") return;
+    const params = new URLSearchParams(searchParams?.toString() ?? "");
+    params.set("provider", next);
+    router.replace(`${pathname}?${params.toString()}`);
+  }
+
+  return (
+    <div className="bg-card border-border space-y-4 rounded-xl border p-6">
+      {/* The card used to render an icon-only header row (Sparkles +
+          status badges, no title), which left the tile unanchored next
+          to its titled siblings. It now follows the shared
+          `SettingsCardHeader` contract: icon column, title + description
+          in the content column, status badges top-right — and the body
+          below indents to the title column (`pl-7`). */}
+      <SettingsCardHeader
+        icon={Sparkles}
+        title={t("settings.ai.providerCardTitle")}
+        description={t("settings.kiInsightsDescription")}
+        status={
+          <ProviderStatusBadges
+            settings={insightsSettings}
+            activeProvider={chainData?.activeProvider ?? null}
+          />
+        }
+      />
+
+      <div className="space-y-4 pl-7">
+        <ActiveProviderSelect
+          value={selectedProvider}
+          onChange={pickProvider}
+        />
+
+        <ProviderConfigCard
+          provider={selectedProvider}
+          insightsSettings={insightsSettings}
+          userProvider={userProvider}
+        />
+
+        <FallbackChainCard
+          chain={chainData?.configuredChain ?? []}
+          selected={selectedProvider}
+          onSelect={pickProvider}
+        />
+
+        <RuntimeActionsRow
+          provider={selectedProvider}
+          userProvider={userProvider}
+          canRegenerate={
+            insightsSettings?.codexStatus === "connected" ||
+            insightsSettings?.hasAdminKey ||
+            Boolean(userProvider?.provider)
+          }
+          privacyMode={insightsSettings?.privacyMode ?? "aggregated"}
+          lastInsightAt={insightsSettings?.lastInsightAt ?? null}
+          onRegenerated={() =>
+            queryClient.invalidateQueries({
+              queryKey: queryKeys.insightsRoot(),
+            })
+          }
+          onPrivacyChanged={() =>
+            queryClient.invalidateQueries({
+              queryKey: queryKeys.insightsRoot(),
+            })
+          }
+        />
+      </div>
+    </div>
+  );
+}
+
+function ProviderStatusBadges({
+  settings,
+  activeProvider,
+}: {
+  settings: InsightsSettings | null | undefined;
+  activeProvider: ProviderType | null;
+}) {
+  const { t } = useTranslations();
+  return (
+    <div className="flex flex-wrap items-center gap-2">
+      {settings?.codexStatus === "connected" && activeProvider === "codex" && (
+        <Badge className="border-success/30 bg-success/15 text-success">
+          {t("settings.ai.chatgptConnectedBadge")}
+        </Badge>
+      )}
+      {settings?.codexStatus !== "connected" &&
+        settings?.hasAdminKey &&
+        activeProvider !== "codex" && (
+          <Badge className="border-primary/30 bg-primary/15 text-primary">
+            {t("settings.ai.adminAiActiveBadge")}
+          </Badge>
+        )}
+      {settings?.codexStatus === "expired" && (
+        <Badge className="border-warning/30 bg-warning/15 text-warning">
+          {t("settings.ai.connectionExpiredBadge")}
+        </Badge>
+      )}
+      {settings?.lastInsightAt && (
+        <Badge variant="outline" className="text-xs">
+          {t("settings.lastGeneratedAt")}:{" "}
+          {formatDateTime(settings.lastInsightAt)}
+        </Badge>
+      )}
+    </div>
+  );
+}
+
+/**
+ * The single Pulldown that drives every form below it. Uses the
+ * shared `<NativeSelect>` primitive so the SSR-only settings test
+ * renders deterministically without a portal-based Radix tree, and so
+ * the visual contract stays uniform with the other settings pickers
+ * that landed behind the same primitive in MB7 / CF-52. Mobile:
+ * full-width, height matched to the shared 36 px input contract used
+ * everywhere else in Settings; tap target stays comfortable thanks to
+ * the full-width chevron region.
+ */
+function ActiveProviderSelect({
+  value,
+  onChange,
+}: {
+  value: ProviderType;
+  onChange: (next: ProviderType) => void;
+}) {
+  const { t } = useTranslations();
+  return (
+    <div className="bg-muted/50 rounded-lg p-4">
+      <p className="text-sm font-medium">
+        {t("settings.ai.activeProviderHeading")}
+      </p>
+      <p className="text-muted-foreground mb-3 text-xs">
+        {t("settings.ai.activeProviderBody")}
+      </p>
+      <Label htmlFor="ai-active-provider-select">
+        {t("settings.ai.activeProviderLabel")}
+      </Label>
+      <NativeSelect
+        id="ai-active-provider-select"
+        data-testid="ai-active-provider-select"
+        value={value}
+        onChange={(e) => {
+          const next = e.target.value;
+          if (isProviderType(next)) onChange(next);
+        }}
+        className="mt-1 sm:max-w-md"
+      >
+        {PROVIDER_TYPES.map((p) => (
+          <option key={p} value={p}>
+            {t(`settings.ai.providerSelect.${p}` as const)}
+          </option>
+        ))}
+      </NativeSelect>
+    </div>
+  );
+}
+
+/**
+ * Switch-rendered provider configuration. The component is the
+ * "form below adapts dynamically" half of the maintainer's pulldown contract:
+ * pick Codex → see Codex form; pick OpenAI → see API-key + model
+ * dropdown + base-URL override. The card frame is the same in every
+ * branch so transitions feel like updating a single concept rather
+ * than swapping pages.
+ */
+function ProviderConfigCard({
+  provider,
+  insightsSettings,
+  userProvider,
+}: {
+  provider: ProviderType;
+  insightsSettings: InsightsSettings | null | undefined;
+  userProvider: UserAIProvider | null | undefined;
+}) {
+  const { t } = useTranslations();
+  return (
+    <div className="bg-muted/50 space-y-4 rounded-lg p-4">
+      <p className="text-sm font-medium">
+        {t("settings.ai.providerConfigTitle")}
+      </p>
+      {provider === "codex" && (
+        <CodexProviderForm settings={insightsSettings} />
+      )}
+      {provider === "openai" && (
+        <OpenAIProviderForm userProvider={userProvider} />
+      )}
+      {provider === "anthropic" && (
+        <AnthropicProviderForm userProvider={userProvider} />
+      )}
+      {provider === "local" && (
+        <LocalProviderForm userProvider={userProvider} />
+      )}
+      {provider === "admin-openai" && (
+        <AdminOpenAIProviderForm hasAdminKey={insightsSettings?.hasAdminKey} />
+      )}
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/anthropic-provider-form.tsx b/src/components/settings/ai/anthropic-provider-form.tsx
new file mode 100644
index 000000000..c7e8b810f
--- /dev/null
+++ b/src/components/settings/ai/anthropic-provider-form.tsx
@@ -0,0 +1,171 @@
+"use client";
+
+/* ────────────────────────────────────────────────────────────────
+ * Anthropic form — API key + model dropdown.
+ * ──────────────────────────────────────────────────────────────── */
+
+import { useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { Loader2, Save } from "lucide-react";
+
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { NativeSelect } from "@/components/ui/native-select";
+import { PasswordInput } from "@/components/ui/password-input";
+import { apiPatch } from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+
+import {
+  ANTHROPIC_MODEL_PRESETS,
+  CUSTOM_MODEL_SENTINEL,
+  uiToLegacyProviderEnum,
+  type UserAIProvider,
+} from "./shared";
+
+export function AnthropicProviderForm({
+  userProvider,
+}: {
+  userProvider: UserAIProvider | null | undefined;
+}) {
+  const { t } = useTranslations();
+  const queryClient = useQueryClient();
+
+  const [apiKey, setApiKey] = useState("");
+  const [modelChoice, setModelChoice] = useState<string>("");
+  const [customModel, setCustomModel] = useState("");
+  const [msg, setMsg] = useState<string | null>(null);
+  const [ok, setOk] = useState(false);
+
+  const seededKey =
+    userProvider != null
+      ? `${userProvider.provider ?? ""}|${userProvider.model ?? ""}`
+      : null;
+  const [previousSeed, setPreviousSeed] = useState<string | null>(null);
+  if (seededKey && seededKey !== previousSeed) {
+    setPreviousSeed(seededKey);
+    if (userProvider?.provider === "ANTHROPIC") {
+      const saved = userProvider.model ?? "";
+      if (
+        saved &&
+        (ANTHROPIC_MODEL_PRESETS as readonly string[]).includes(saved)
+      ) {
+        setModelChoice(saved);
+        setCustomModel("");
+      } else if (saved) {
+        setModelChoice(CUSTOM_MODEL_SENTINEL);
+        setCustomModel(saved);
+      }
+    }
+  }
+
+  const effectiveModel =
+    modelChoice === CUSTOM_MODEL_SENTINEL
+      ? customModel.trim()
+      : modelChoice.trim();
+
+  const saveMutation = useMutation({
+    mutationFn: async () => {
+      const body: Record<string, unknown> = {
+        provider: uiToLegacyProviderEnum("anthropic"),
+        model: effectiveModel || null,
+      };
+      if (apiKey.trim()) body.anthropicKey = apiKey.trim();
+      await apiPatch("/api/user/ai-provider", body);
+    },
+    onSuccess: () => {
+      setOk(true);
+      setMsg(t("settings.ai.saved"));
+      setApiKey("");
+      queryClient.invalidateQueries({ queryKey: queryKeys.userAiProvider() });
+      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
+    },
+    onError: (e) => {
+      setOk(false);
+      setMsg(e instanceof Error ? e.message : t("settings.ai.errorGeneric"));
+    },
+  });
+
+  return (
+    <div data-testid="ai-provider-config-anthropic" className="space-y-4">
+      <div>
+        <Label htmlFor="ai-anthropic-key">
+          {t("settings.ai.anthropicKeyLabel")}
+          {userProvider?.hasAnthropicKey && (
+            <span className="text-muted-foreground ml-2 text-xs">
+              {t("settings.ai.savedPreview", {
+                preview: userProvider.anthropicKeyPreview ?? "",
+              })}
+            </span>
+          )}
+        </Label>
+        <PasswordInput
+          id="ai-anthropic-key"
+          value={apiKey}
+          onChange={(e) => setApiKey(e.target.value)}
+          placeholder="sk-ant-…"
+          className="mt-1"
+        />
+      </div>
+
+      <div>
+        <Label htmlFor="ai-anthropic-model">
+          {t("settings.ai.modelLabel")}
+        </Label>
+        <NativeSelect
+          id="ai-anthropic-model"
+          value={modelChoice}
+          onChange={(e) => setModelChoice(e.target.value)}
+          className="mt-1"
+        >
+          <option value="">{t("settings.ai.modelOptionDefault")}</option>
+          {ANTHROPIC_MODEL_PRESETS.map((m) => (
+            <option key={m} value={m}>
+              {m}
+            </option>
+          ))}
+          <option value={CUSTOM_MODEL_SENTINEL}>
+            {t("settings.ai.modelOptionCustom")}
+          </option>
+        </NativeSelect>
+      </div>
+
+      {modelChoice === CUSTOM_MODEL_SENTINEL && (
+        <div>
+          <Label htmlFor="ai-anthropic-model-custom">
+            {t("settings.ai.customModelLabel")}
+          </Label>
+          <Input
+            id="ai-anthropic-model-custom"
+            value={customModel}
+            onChange={(e) => setCustomModel(e.target.value)}
+            placeholder="claude-3-5-sonnet-latest"
+            className="mt-1"
+          />
+        </div>
+      )}
+
+      <div>
+        <Button
+          size="sm"
+          onClick={() => saveMutation.mutate()}
+          disabled={saveMutation.isPending}
+        >
+          {saveMutation.isPending ? (
+            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+          ) : (
+            <Save className="h-4 w-4" />
+          )}
+          {t("settings.ai.saveCta")}
+        </Button>
+      </div>
+
+      {msg && (
+        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
+          {msg}
+        </p>
+      )}
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/codex-provider-form.tsx b/src/components/settings/ai/codex-provider-form.tsx
new file mode 100644
index 000000000..ef10525f3
--- /dev/null
+++ b/src/components/settings/ai/codex-provider-form.tsx
@@ -0,0 +1,298 @@
+"use client";
+
+/* ────────────────────────────────────────────────────────────────
+ * Codex (ChatGPT account) form — connect / disconnect / status.
+ * ──────────────────────────────────────────────────────────────── */
+
+import { useEffect, useState } from "react";
+import { useQueryClient } from "@tanstack/react-query";
+import { Loader2, Sparkles, Trash2 } from "lucide-react";
+
+import { Badge } from "@/components/ui/badge";
+import { Button } from "@/components/ui/button";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
+import { formatDateTime } from "@/lib/format";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+
+import type { InsightsSettings } from "./shared";
+
+export function CodexProviderForm({
+  settings,
+}: {
+  settings: InsightsSettings | null | undefined;
+}) {
+  const { t } = useTranslations();
+  const queryClient = useQueryClient();
+
+  const [msg, setMsg] = useState<string | null>(null);
+  const [msgType, setMsgType] = useState<"success" | "error" | null>(null);
+  const [disconnecting, setDisconnecting] = useState(false);
+  const [deviceCode, setDeviceCode] = useState<{
+    userCode: string;
+    verificationUrl: string;
+    intervalSeconds: number;
+  } | null>(null);
+  const [devicePolling, setDevicePolling] = useState(false);
+
+  // OAuth callback handler — reads `?codex_connected=true|codex_error=…`
+  // from the URL and surfaces an inline message.
+  const [oauthOutcome] = useState<
+    { kind: "connected" } | { kind: "error" } | null
+  >(() => {
+    if (typeof window === "undefined") return null;
+    const params = new URLSearchParams(window.location.search);
+    if (params.get("codex_connected") === "true") return { kind: "connected" };
+    if (params.get("codex_error")) return { kind: "error" };
+    return null;
+  });
+
+  useEffect(() => {
+    if (!oauthOutcome) return;
+    const url = new URL(window.location.href);
+    url.searchParams.delete("codex_connected");
+    url.searchParams.delete("codex_error");
+    window.history.replaceState({}, "", url.toString());
+    if (oauthOutcome.kind === "connected") {
+      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
+    }
+  }, [oauthOutcome, queryClient]);
+
+  const [oauthMsgSeeded, setOauthMsgSeeded] = useState(false);
+  if (!oauthMsgSeeded && oauthOutcome) {
+    setOauthMsgSeeded(true);
+    if (oauthOutcome.kind === "connected") {
+      setMsg(t("settings.codexConnected"));
+      setMsgType("success");
+    } else {
+      setMsg(t("settings.codexConnectionFailed"));
+      setMsgType("error");
+    }
+  }
+
+  async function handleConnect() {
+    setMsg(null);
+    setDevicePolling(true);
+    try {
+      const res = await apiFetchRaw("/api/auth/codex/device-start", {
+        method: "POST",
+      });
+      const json = await res.json();
+      if (!res.ok) throw new Error(json.error || t("settings.savingError"));
+      setDeviceCode({
+        userCode: json.data.userCode,
+        verificationUrl: json.data.verificationUrl,
+        intervalSeconds: json.data.intervalSeconds,
+      });
+    } catch (err) {
+      setMsg(err instanceof Error ? err.message : t("settings.savingError"));
+      setMsgType("error");
+      setDevicePolling(false);
+    }
+  }
+
+  useEffect(() => {
+    if (!deviceCode) return;
+    let cancelled = false;
+    const intervalMs = Math.max(deviceCode.intervalSeconds, 3) * 1000;
+
+    async function tick() {
+      try {
+        const res = await apiFetchRaw("/api/auth/codex/device-poll", {
+          method: "POST",
+        });
+        const json = await res.json();
+        if (cancelled) return;
+        if (!res.ok) {
+          throw new Error(json.error || t("settings.savingError"));
+        }
+        if (json.data?.status === "connected") {
+          setDeviceCode(null);
+          setDevicePolling(false);
+          setMsg(t("settings.codexConnected"));
+          setMsgType("success");
+          queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
+          return;
+        }
+        if (!cancelled) setTimeout(tick, intervalMs);
+      } catch (err) {
+        if (cancelled) return;
+        setMsg(err instanceof Error ? err.message : t("settings.savingError"));
+        setMsgType("error");
+        setDeviceCode(null);
+        setDevicePolling(false);
+      }
+    }
+
+    const handle = setTimeout(tick, intervalMs);
+    return () => {
+      cancelled = true;
+      clearTimeout(handle);
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [deviceCode]);
+
+  function handleCancelDevice() {
+    setDeviceCode(null);
+    setDevicePolling(false);
+  }
+
+  async function handleDisconnect() {
+    setDisconnecting(true);
+    setMsg(null);
+    try {
+      const res = await apiFetchRaw("/api/auth/codex/disconnect", {
+        method: "DELETE",
+      });
+      if (!res.ok) {
+        const json = await res.json();
+        throw new Error(json.error);
+      }
+      setMsg(t("settings.codexDisconnected"));
+      setMsgType("success");
+      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
+    } catch (err) {
+      setMsg(err instanceof Error ? err.message : t("settings.savingError"));
+      setMsgType("error");
+    } finally {
+      setDisconnecting(false);
+    }
+  }
+
+  const status = settings?.codexStatus;
+  const isConnected = status === "connected";
+
+  return (
+    <div data-testid="ai-provider-config-codex" className="space-y-4">
+      <div className="flex flex-wrap items-center gap-2 text-sm">
+        <span className="font-medium">
+          {t("settings.ai.codex.modelSlugLabel")}
+        </span>
+        {isConnected ? (
+          <Badge className="border-success/30 bg-success/15 text-success">
+            {t("settings.ai.codex.statusConnected")}
+          </Badge>
+        ) : status === "expired" ? (
+          <Badge className="border-warning/30 bg-warning/15 text-warning">
+            {t("settings.ai.codex.statusExpired")}
+          </Badge>
+        ) : (
+          <Badge variant="outline">
+            {t("settings.ai.codex.statusDisconnected")}
+          </Badge>
+        )}
+      </div>
+      <p className="text-muted-foreground text-xs">
+        {t("settings.ai.codex.modelSlugBody")}
+      </p>
+      {settings?.lastInsightAt && (
+        <p className="text-muted-foreground text-xs">
+          {t("settings.ai.codex.lastInsight", {
+            when: formatDateTime(settings.lastInsightAt),
+          })}
+        </p>
+      )}
+      {settings?.codexConnectedAt && isConnected && (
+        <p className="text-muted-foreground text-xs">
+          {t("settings.ai.connectedSince", {
+            when: formatDateTime(settings.codexConnectedAt),
+          })}
+        </p>
+      )}
+
+      {settings?.codexOauthConfigured === false ? (
+        <p className="text-muted-foreground text-xs italic">
+          {t("settings.ai.oauthNotConfigured")}
+        </p>
+      ) : isConnected ? (
+        <Button
+          variant="outline"
+          size="sm"
+          className="text-destructive shrink-0"
+          onClick={handleDisconnect}
+          disabled={disconnecting}
+        >
+          {disconnecting ? (
+            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+          ) : (
+            <Trash2 className="h-4 w-4" />
+          )}
+          {t("settings.ai.codex.disconnectButton")}
+        </Button>
+      ) : deviceCode ? (
+        <div className="border-primary bg-primary/5 space-y-3 rounded-lg border-l-4 p-4">
+          <p className="text-sm font-medium">
+            {t("settings.ai.deviceCodeHeading")}
+          </p>
+          <ol className="text-muted-foreground list-decimal space-y-2 pl-5 text-sm">
+            <li>
+              {t("settings.ai.deviceCodeStep1")}{" "}
+              <a
+                href={deviceCode.verificationUrl}
+                target="_blank"
+                rel="noopener noreferrer"
+                className="text-primary font-medium underline"
+              >
+                {deviceCode.verificationUrl}
+              </a>
+            </li>
+            <li>
+              {t("settings.ai.deviceCodeStep2")}
+              <div className="bg-card border-border mt-2 inline-flex items-center gap-2 rounded border px-3 py-2 font-mono text-lg tracking-widest">
+                {deviceCode.userCode}
+                <button
+                  type="button"
+                  onClick={() =>
+                    navigator.clipboard?.writeText(deviceCode.userCode)
+                  }
+                  className="text-muted-foreground hover:text-foreground text-xs underline"
+                >
+                  {t("settings.ai.deviceCodeCopy")}
+                </button>
+              </div>
+            </li>
+            <li>{t("settings.ai.deviceCodeStep3")}</li>
+          </ol>
+          <div className="flex items-center gap-3 text-xs">
+            {devicePolling && (
+              <span className="text-muted-foreground inline-flex items-center gap-1">
+                <Loader2 className="h-3 w-3 animate-spin motion-reduce:animate-none" />
+                {t("settings.ai.deviceCodeWaiting")}
+              </span>
+            )}
+            <button
+              type="button"
+              onClick={handleCancelDevice}
+              className="text-muted-foreground hover:text-foreground underline"
+            >
+              {t("settings.ai.deviceCodeCancel")}
+            </button>
+          </div>
+        </div>
+      ) : (
+        <Button
+          variant="outline"
+          onClick={handleConnect}
+          disabled={devicePolling}
+          className="w-full sm:w-auto"
+        >
+          {devicePolling ? (
+            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+          ) : (
+            <Sparkles className="h-4 w-4" />
+          )}
+          {t("settings.ai.codex.connectButton")}
+        </Button>
+      )}
+
+      {msg && (
+        <p
+          role="alert"
+          className={`text-sm ${msgType === "success" ? "text-success" : "text-destructive"}`}
+        >
+          {msg}
+        </p>
+      )}
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/disable-coach-card.tsx b/src/components/settings/ai/disable-coach-card.tsx
new file mode 100644
index 000000000..aa6615fd3
--- /dev/null
+++ b/src/components/settings/ai/disable-coach-card.tsx
@@ -0,0 +1,157 @@
+"use client";
+
+/**
+ * v1.4.47 W3 — "Hide Coach" toggle card.
+ *
+ * Persists via `PATCH /api/auth/me/disable-coach`; the response
+ * invalidates `queryKeys.authMe()` so every Coach mount point on the
+ * client (`<LayoutCoachFab>`, `<LayoutCoachMount>`, the inline
+ * `<CoachLaunchButton>` pill, the `/targets` page CTAs) re-renders
+ * with the new `user.disableCoach` value on the next React Query
+ * refetch tick — no full reload required.
+ *
+ * The optimistic-update pattern mirrors `<MoodReminderCard>`: the
+ * Switch flips immediately, the mutation rolls back on error.
+ *
+ * v1.16.4 — header follows the shared `SettingsCardHeader` contract
+ * (icon column + title + switch in the status slot) so the card reads
+ * like its siblings instead of carrying its own bespoke header row.
+ */
+
+import { useEffect, useRef, useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { MessageCircleOff } from "lucide-react";
+
+import { Switch } from "@/components/ui/switch";
+import { SettingsCardHeader } from "@/components/settings/_card-header";
+import { apiPatch } from "@/lib/api/api-fetch";
+import { useAuth } from "@/hooks/use-auth";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+
+export function DisableCoachCard({
+  isAuthenticated,
+}: {
+  isAuthenticated: boolean;
+}) {
+  const { t } = useTranslations();
+  const queryClient = useQueryClient();
+  const { user } = useAuth();
+
+  // Optimistic-update flag — null means "no in-flight change",
+  // otherwise it overrides the wire value until the mutation
+  // settles. Mirrors the `<MoodReminderCard>` pattern so the Switch
+  // reacts instantly to the user's tap.
+  const [optimistic, setOptimistic] = useState<boolean | null>(null);
+  const [msg, setMsg] = useState<string | null>(null);
+  const [msgType, setMsgType] = useState<"success" | "error" | null>(null);
+
+  // v1.4.48 M2 — auto-clear the inline `<p role="status">` line 3 s
+  // after the mutation settles so a Settings card the user scrolled
+  // past minutes earlier doesn't keep echoing a stale "Coach hidden"
+  // banner. The ref tracks the in-flight timer so we can clear it on
+  // unmount + on a follow-up toggle (otherwise a rapid double-tap
+  // could leave a stray timer pointing at a stale message).
+  const clearTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    return () => {
+      if (clearTimerRef.current !== null) {
+        clearTimeout(clearTimerRef.current);
+        clearTimerRef.current = null;
+      }
+    };
+  }, []);
+
+  function scheduleClear() {
+    if (clearTimerRef.current !== null) {
+      clearTimeout(clearTimerRef.current);
+    }
+    clearTimerRef.current = setTimeout(() => {
+      clearTimerRef.current = null;
+      setMsg(null);
+      setMsgType(null);
+    }, 3000);
+  }
+
+  const checked = optimistic ?? user?.disableCoach ?? false;
+
+  const mutation = useMutation({
+    mutationFn: async (next: boolean) => {
+      await apiPatch("/api/auth/me/disable-coach", { disableCoach: next });
+      return next;
+    },
+    onSuccess: (next) => {
+      setMsg(
+        next
+          ? t("settings.ai.disableCoach.savedHidden")
+          : t("settings.ai.disableCoach.savedShown"),
+      );
+      setMsgType("success");
+      // Surface the new value to every Coach gate via the shared
+      // `useAuth()` query — the gates re-render once React Query
+      // re-fetches /api/auth/me with the updated `disableCoach` field.
+      queryClient.invalidateQueries({ queryKey: queryKeys.authMe() });
+      setOptimistic(null);
+      scheduleClear();
+    },
+    onError: (err) => {
+      setOptimistic(null);
+      setMsg(
+        err instanceof Error
+          ? err.message
+          : t("settings.ai.disableCoach.saveError"),
+      );
+      setMsgType("error");
+      scheduleClear();
+    },
+  });
+
+  function handleToggle(next: boolean) {
+    setOptimistic(next);
+    setMsg(null);
+    setMsgType(null);
+    if (clearTimerRef.current !== null) {
+      clearTimeout(clearTimerRef.current);
+      clearTimerRef.current = null;
+    }
+    mutation.mutate(next);
+  }
+
+  return (
+    <section
+      aria-labelledby="settings-ai-disable-coach-title"
+      data-testid="settings-disable-coach-card"
+      className="bg-card border-border rounded-xl border p-6"
+    >
+      <SettingsCardHeader
+        icon={MessageCircleOff}
+        title={t("settings.ai.disableCoach.title")}
+        titleId="settings-ai-disable-coach-title"
+        description={t("settings.ai.disableCoach.description")}
+        status={
+          <Switch
+            data-testid="settings-disable-coach-switch"
+            checked={checked}
+            onCheckedChange={handleToggle}
+            disabled={!isAuthenticated || mutation.isPending}
+            aria-label={t("settings.ai.disableCoach.toggleAria")}
+          />
+        }
+      />
+      {msg && (
+        <p
+          role="status"
+          aria-live="polite"
+          className={
+            msgType === "error"
+              ? "text-destructive mt-3 pl-7 text-xs"
+              : "text-muted-foreground mt-3 pl-7 text-xs"
+          }
+        >
+          {msg}
+        </p>
+      )}
+    </section>
+  );
+}
diff --git a/src/components/settings/ai/fallback-chain-card.tsx b/src/components/settings/ai/fallback-chain-card.tsx
new file mode 100644
index 000000000..06122f91d
--- /dev/null
+++ b/src/components/settings/ai/fallback-chain-card.tsx
@@ -0,0 +1,320 @@
+"use client";
+
+/* ────────────────────────────────────────────────────────────────
+ * Fallback chain card — reorder via arrows, toggle, remove, add,
+ * reset. Uses no new dependency (dnd-kit isn't in package.json).
+ * ──────────────────────────────────────────────────────────────── */
+
+import { useMemo, useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import {
+  ArrowDown,
+  ArrowUp,
+  Loader2,
+  PlusCircle,
+  RotateCcw,
+  Save,
+  X,
+} from "lucide-react";
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from "@/components/ui/alert-dialog";
+import { Button } from "@/components/ui/button";
+import { NativeSelect } from "@/components/ui/native-select";
+import { Switch } from "@/components/ui/switch";
+import { apiPut } from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+
+import {
+  DEFAULT_CHAIN,
+  PROVIDER_TYPES,
+  isProviderType,
+  type ChainEntry,
+  type ProviderType,
+} from "./shared";
+
+export function FallbackChainCard({
+  chain,
+  selected,
+  onSelect,
+}: {
+  chain: {
+    providerType: ProviderType;
+    enabled: boolean;
+    available: boolean;
+  }[];
+  selected: ProviderType;
+  onSelect: (next: ProviderType) => void;
+}) {
+  const { t } = useTranslations();
+  const queryClient = useQueryClient();
+
+  // Local working copy. Server-confirmed values arrive via `chain`
+  // prop; we keep our own state so the user can shuffle multiple rows
+  // before clicking "Save chain order".
+  // v1.4.16 phase D reconcile (code-review H2) — `enabled` from the
+  // wire is now the canonical state. The GET endpoint surfaces the
+  // raw persisted chain so a disabled entry survives the round-trip.
+  const seededKey = chain
+    .map((c) => `${c.providerType}:${c.enabled ? 1 : 0}`)
+    .join(",");
+  const [seeded, setSeeded] = useState<string | null>(null);
+  const [entries, setEntries] = useState<ChainEntry[]>(() =>
+    chain.map((c) => ({ providerType: c.providerType, enabled: c.enabled })),
+  );
+  if (seededKey !== seeded) {
+    setSeeded(seededKey);
+    setEntries(
+      chain.map((c) => ({
+        providerType: c.providerType,
+        enabled: c.enabled,
+      })),
+    );
+  }
+
+  const [msg, setMsg] = useState<string | null>(null);
+  const [ok, setOk] = useState(false);
+
+  const saveMutation = useMutation({
+    mutationFn: async (next: ChainEntry[]) => {
+      const body = {
+        chain: next.map((entry, idx) => ({
+          providerType: entry.providerType,
+          priority: idx + 1,
+          enabled: entry.enabled,
+        })),
+      };
+      await apiPut("/api/insights/provider-chain", body);
+    },
+    onSuccess: () => {
+      setOk(true);
+      setMsg(t("settings.ai.providerChain.saved"));
+      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
+    },
+    onError: (e) => {
+      setOk(false);
+      setMsg(
+        e instanceof Error
+          ? e.message
+          : t("settings.ai.providerChain.saveFailed"),
+      );
+    },
+  });
+
+  function move(idx: number, delta: -1 | 1) {
+    setEntries((prev) => {
+      const next = [...prev];
+      const target = idx + delta;
+      if (target < 0 || target >= next.length) return prev;
+      [next[idx], next[target]] = [next[target], next[idx]];
+      return next;
+    });
+  }
+
+  function toggle(idx: number) {
+    setEntries((prev) => {
+      const next = [...prev];
+      next[idx] = { ...next[idx], enabled: !next[idx].enabled };
+      return next;
+    });
+  }
+
+  function remove(idx: number) {
+    setEntries((prev) => prev.filter((_, i) => i !== idx));
+  }
+
+  const present = useMemo(
+    () => new Set(entries.map((e) => e.providerType)),
+    [entries],
+  );
+  const addable = PROVIDER_TYPES.filter((p) => !present.has(p));
+
+  function add(p: ProviderType) {
+    setEntries((prev) => [...prev, { providerType: p, enabled: true }]);
+  }
+
+  function resetToDefaults() {
+    setEntries(DEFAULT_CHAIN.map((d) => ({ ...d })));
+  }
+
+  return (
+    <div
+      data-testid="ai-fallback-chain"
+      className="bg-muted/50 space-y-3 rounded-lg p-4"
+    >
+      <div>
+        <p className="text-sm font-medium">
+          {t("settings.ai.providerChain.title")}
+        </p>
+        <p className="text-muted-foreground text-xs">
+          {t("settings.ai.providerChain.description")}
+        </p>
+      </div>
+
+      <ul className="space-y-2">
+        {entries.map((entry, idx) => (
+          <li
+            key={entry.providerType}
+            data-chain-row={entry.providerType}
+            className={`bg-card border-border flex flex-wrap items-center gap-2 rounded-md border p-2 ${
+              entry.providerType === selected
+                ? "border-primary/40 ring-primary/30 ring-1"
+                : ""
+            }`}
+          >
+            <span className="text-muted-foreground w-5 text-center text-xs tabular-nums">
+              {idx + 1}.
+            </span>
+            <button
+              type="button"
+              onClick={() => onSelect(entry.providerType)}
+              className="flex-1 text-left text-sm font-medium hover:underline"
+            >
+              {t(`settings.ai.providerChain.types.${entry.providerType}`)}
+            </button>
+            <Switch
+              checked={entry.enabled}
+              onCheckedChange={() => toggle(idx)}
+              aria-label={t(
+                `settings.ai.providerChain.types.${entry.providerType}`,
+              )}
+            />
+            <Button
+              type="button"
+              size="sm"
+              variant="outline"
+              aria-label={t("settings.ai.providerChain.moveUp")}
+              disabled={idx === 0}
+              onClick={() => move(idx, -1)}
+            >
+              <ArrowUp className="h-4 w-4" />
+            </Button>
+            <Button
+              type="button"
+              size="sm"
+              variant="outline"
+              aria-label={t("settings.ai.providerChain.moveDown")}
+              disabled={idx === entries.length - 1}
+              onClick={() => move(idx, 1)}
+            >
+              <ArrowDown className="h-4 w-4" />
+            </Button>
+            <Button
+              type="button"
+              size="sm"
+              variant="outline"
+              aria-label={t("settings.ai.providerChain.removeFromChain")}
+              className="text-destructive"
+              onClick={() => remove(idx)}
+              disabled={entries.length <= 1}
+            >
+              <X className="h-4 w-4" />
+            </Button>
+          </li>
+        ))}
+      </ul>
+
+      <div className="flex flex-wrap items-center gap-2">
+        {addable.length > 0 ? (
+          <AddProviderControl addable={addable} onAdd={add} />
+        ) : (
+          <p className="text-muted-foreground text-xs italic">
+            {t("settings.ai.providerChain.addNoneAvailable")}
+          </p>
+        )}
+        <Button
+          size="sm"
+          onClick={() => saveMutation.mutate(entries)}
+          disabled={saveMutation.isPending || entries.length === 0}
+          data-testid="ai-fallback-chain-save"
+        >
+          {saveMutation.isPending ? (
+            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+          ) : (
+            <Save className="h-4 w-4" />
+          )}
+          {t("settings.ai.providerChain.saveOrder")}
+        </Button>
+        <AlertDialog>
+          <AlertDialogTrigger asChild>
+            <Button size="sm" variant="outline">
+              <RotateCcw className="h-4 w-4" />
+              {t("settings.ai.providerChain.resetDefaults")}
+            </Button>
+          </AlertDialogTrigger>
+          <AlertDialogContent>
+            <AlertDialogHeader>
+              <AlertDialogTitle>
+                {t("settings.ai.providerChain.resetConfirmTitle")}
+              </AlertDialogTitle>
+              <AlertDialogDescription>
+                {t("settings.ai.providerChain.resetConfirmBody")}
+              </AlertDialogDescription>
+            </AlertDialogHeader>
+            <AlertDialogFooter>
+              <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+              <AlertDialogAction onClick={resetToDefaults}>
+                {t("settings.ai.providerChain.resetDefaults")}
+              </AlertDialogAction>
+            </AlertDialogFooter>
+          </AlertDialogContent>
+        </AlertDialog>
+      </div>
+
+      {msg && (
+        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
+          {msg}
+        </p>
+      )}
+    </div>
+  );
+}
+
+function AddProviderControl({
+  addable,
+  onAdd,
+}: {
+  addable: readonly ProviderType[];
+  onAdd: (p: ProviderType) => void;
+}) {
+  const { t } = useTranslations();
+  const [picked, setPicked] = useState<string>(addable[0] ?? "");
+
+  return (
+    <div className="flex items-center gap-2">
+      <NativeSelect
+        aria-label={t("settings.ai.providerChain.addProvider")}
+        value={picked}
+        onChange={(e) => setPicked(e.target.value)}
+        className="w-auto"
+      >
+        {addable.map((p) => (
+          <option key={p} value={p}>
+            {t(`settings.ai.providerChain.types.${p}`)}
+          </option>
+        ))}
+      </NativeSelect>
+      <Button
+        type="button"
+        size="sm"
+        variant="outline"
+        onClick={() => {
+          if (isProviderType(picked)) onAdd(picked);
+        }}
+      >
+        <PlusCircle className="h-4 w-4" />
+        {t("settings.ai.providerChain.addProvider")}
+      </Button>
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/local-provider-form.tsx b/src/components/settings/ai/local-provider-form.tsx
new file mode 100644
index 000000000..7c18a92f7
--- /dev/null
+++ b/src/components/settings/ai/local-provider-form.tsx
@@ -0,0 +1,172 @@
+"use client";
+
+/* ────────────────────────────────────────────────────────────────
+ * Local (OpenAI-compatible) form — base URL + optional key + model.
+ * ──────────────────────────────────────────────────────────────── */
+
+import { useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { Loader2, Save } from "lucide-react";
+
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { NativeSelect } from "@/components/ui/native-select";
+import { PasswordInput } from "@/components/ui/password-input";
+import { apiPatch } from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+
+import {
+  CUSTOM_MODEL_SENTINEL,
+  LOCAL_MODEL_PRESETS,
+  uiToLegacyProviderEnum,
+  type UserAIProvider,
+} from "./shared";
+
+export function LocalProviderForm({
+  userProvider,
+}: {
+  userProvider: UserAIProvider | null | undefined;
+}) {
+  const { t } = useTranslations();
+  const queryClient = useQueryClient();
+
+  const [baseUrl, setBaseUrl] = useState("");
+  const [apiKey, setApiKey] = useState("");
+  const [modelChoice, setModelChoice] = useState<string>("");
+  const [customModel, setCustomModel] = useState("");
+  const [msg, setMsg] = useState<string | null>(null);
+  const [ok, setOk] = useState(false);
+
+  const seededKey =
+    userProvider != null
+      ? `${userProvider.provider ?? ""}|${userProvider.model ?? ""}|${userProvider.baseUrl ?? ""}`
+      : null;
+  const [previousSeed, setPreviousSeed] = useState<string | null>(null);
+  if (seededKey && seededKey !== previousSeed) {
+    setPreviousSeed(seededKey);
+    if (userProvider?.provider === "LOCAL") {
+      setBaseUrl(userProvider.baseUrl ?? "");
+      const saved = userProvider.model ?? "";
+      if (saved && (LOCAL_MODEL_PRESETS as readonly string[]).includes(saved)) {
+        setModelChoice(saved);
+        setCustomModel("");
+      } else if (saved) {
+        setModelChoice(CUSTOM_MODEL_SENTINEL);
+        setCustomModel(saved);
+      }
+    }
+  }
+
+  const effectiveModel =
+    modelChoice === CUSTOM_MODEL_SENTINEL
+      ? customModel.trim()
+      : modelChoice.trim();
+
+  const saveMutation = useMutation({
+    mutationFn: async () => {
+      const body: Record<string, unknown> = {
+        provider: uiToLegacyProviderEnum("local"),
+        baseUrl: baseUrl.trim() || null,
+        model: effectiveModel || null,
+      };
+      if (apiKey.trim()) body.localKey = apiKey.trim();
+      await apiPatch("/api/user/ai-provider", body);
+    },
+    onSuccess: () => {
+      setOk(true);
+      setMsg(t("settings.ai.saved"));
+      setApiKey("");
+      queryClient.invalidateQueries({ queryKey: queryKeys.userAiProvider() });
+      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
+    },
+    onError: (e) => {
+      setOk(false);
+      setMsg(e instanceof Error ? e.message : t("settings.ai.errorGeneric"));
+    },
+  });
+
+  return (
+    <div data-testid="ai-provider-config-local" className="space-y-4">
+      <div>
+        <Label htmlFor="ai-local-base-url">
+          {t("settings.ai.baseUrlLabel")}
+        </Label>
+        <Input
+          id="ai-local-base-url"
+          value={baseUrl}
+          onChange={(e) => setBaseUrl(e.target.value)}
+          placeholder="http://localhost:11434/v1"
+          className="mt-1"
+        />
+      </div>
+      <div>
+        <Label htmlFor="ai-local-key">{t("settings.ai.localKeyLabel")}</Label>
+        <PasswordInput
+          id="ai-local-key"
+          value={apiKey}
+          onChange={(e) => setApiKey(e.target.value)}
+          placeholder={
+            userProvider?.hasLocalKey ? t("settings.ai.savedShort") : ""
+          }
+          className="mt-1"
+        />
+      </div>
+      <div>
+        <Label htmlFor="ai-local-model">{t("settings.ai.modelLabel")}</Label>
+        <NativeSelect
+          id="ai-local-model"
+          value={modelChoice}
+          onChange={(e) => setModelChoice(e.target.value)}
+          className="mt-1"
+        >
+          <option value="">{t("settings.ai.modelOptionDefault")}</option>
+          {LOCAL_MODEL_PRESETS.map((m) => (
+            <option key={m} value={m}>
+              {m}
+            </option>
+          ))}
+          <option value={CUSTOM_MODEL_SENTINEL}>
+            {t("settings.ai.modelOptionCustom")}
+          </option>
+        </NativeSelect>
+      </div>
+      {modelChoice === CUSTOM_MODEL_SENTINEL && (
+        <div>
+          <Label htmlFor="ai-local-model-custom">
+            {t("settings.ai.customModelLabel")}
+          </Label>
+          <Input
+            id="ai-local-model-custom"
+            value={customModel}
+            onChange={(e) => setCustomModel(e.target.value)}
+            placeholder="llama3:8b"
+            className="mt-1"
+          />
+        </div>
+      )}
+
+      <div>
+        <Button
+          size="sm"
+          onClick={() => saveMutation.mutate()}
+          disabled={saveMutation.isPending}
+        >
+          {saveMutation.isPending ? (
+            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+          ) : (
+            <Save className="h-4 w-4" />
+          )}
+          {t("settings.ai.saveCta")}
+        </Button>
+      </div>
+
+      {msg && (
+        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
+          {msg}
+        </p>
+      )}
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/openai-provider-form.tsx b/src/components/settings/ai/openai-provider-form.tsx
new file mode 100644
index 000000000..98110edec
--- /dev/null
+++ b/src/components/settings/ai/openai-provider-form.tsx
@@ -0,0 +1,208 @@
+"use client";
+
+/* ────────────────────────────────────────────────────────────────
+ * OpenAI form — API key + model select + collapsed Base URL override.
+ * Save mutation flips both `aiProvider` (for the legacy single-result
+ * resolver) and `aiOpenaiKeyEncrypted` (the user's key) so an OPENAI
+ * pick is visible to every code path that reads the row.
+ * ──────────────────────────────────────────────────────────────── */
+
+import { useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { Loader2, Save } from "lucide-react";
+
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { NativeSelect } from "@/components/ui/native-select";
+import { PasswordInput } from "@/components/ui/password-input";
+import { apiPatch } from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
+import { queryKeys } from "@/lib/query-keys";
+
+import {
+  CUSTOM_MODEL_SENTINEL,
+  OPENAI_MODEL_PRESETS,
+  uiToLegacyProviderEnum,
+  type UserAIProvider,
+} from "./shared";
+
+export function OpenAIProviderForm({
+  userProvider,
+}: {
+  userProvider: UserAIProvider | null | undefined;
+}) {
+  const { t } = useTranslations();
+  const queryClient = useQueryClient();
+
+  const [apiKey, setApiKey] = useState("");
+  const [modelChoice, setModelChoice] = useState<string>("");
+  const [customModel, setCustomModel] = useState("");
+  const [baseUrl, setBaseUrl] = useState("");
+  const [showAdvanced, setShowAdvanced] = useState(false);
+  const [msg, setMsg] = useState<string | null>(null);
+  const [ok, setOk] = useState(false);
+
+  const seededKey =
+    userProvider != null
+      ? `${userProvider.provider ?? ""}|${userProvider.model ?? ""}|${userProvider.baseUrl ?? ""}`
+      : null;
+  const [previousSeed, setPreviousSeed] = useState<string | null>(null);
+  if (seededKey && seededKey !== previousSeed) {
+    setPreviousSeed(seededKey);
+    if (userProvider?.provider === "OPENAI") {
+      const saved = userProvider.model ?? "";
+      if (
+        saved &&
+        (OPENAI_MODEL_PRESETS as readonly string[]).includes(saved)
+      ) {
+        setModelChoice(saved);
+        setCustomModel("");
+      } else if (saved) {
+        setModelChoice(CUSTOM_MODEL_SENTINEL);
+        setCustomModel(saved);
+      }
+      setBaseUrl(userProvider.baseUrl ?? "");
+    }
+  }
+
+  const effectiveModel =
+    modelChoice === CUSTOM_MODEL_SENTINEL
+      ? customModel.trim()
+      : modelChoice.trim();
+
+  const saveMutation = useMutation({
+    mutationFn: async () => {
+      const body: Record<string, unknown> = {
+        provider: uiToLegacyProviderEnum("openai"),
+        model: effectiveModel || null,
+        baseUrl: baseUrl.trim() || null,
+      };
+      if (apiKey.trim()) body.openaiKey = apiKey.trim();
+      await apiPatch("/api/user/ai-provider", body);
+    },
+    onSuccess: () => {
+      setOk(true);
+      setMsg(t("settings.ai.saved"));
+      setApiKey("");
+      queryClient.invalidateQueries({ queryKey: queryKeys.userAiProvider() });
+      queryClient.invalidateQueries({ queryKey: queryKeys.insightsRoot() });
+    },
+    onError: (e) => {
+      setOk(false);
+      setMsg(e instanceof Error ? e.message : t("settings.ai.errorGeneric"));
+    },
+  });
+
+  return (
+    <div data-testid="ai-provider-config-openai" className="space-y-4">
+      <div>
+        <Label htmlFor="ai-openai-key">
+          {t("settings.ai.openai.apiKey")}
+          {userProvider?.hasOpenaiKey && (
+            <span className="text-muted-foreground ml-2 text-xs">
+              {t("settings.ai.savedPreview", {
+                preview: userProvider.openaiKeyPreview ?? "",
+              })}
+            </span>
+          )}
+        </Label>
+        <PasswordInput
+          id="ai-openai-key"
+          data-testid="ai-openai-api-key"
+          value={apiKey}
+          onChange={(e) => setApiKey(e.target.value)}
+          placeholder={t("settings.ai.openai.apiKeyPlaceholder")}
+          className="mt-1"
+        />
+      </div>
+
+      <div>
+        <Label htmlFor="ai-openai-model">
+          {t("settings.ai.openai.modelSelect")}
+        </Label>
+        <NativeSelect
+          id="ai-openai-model"
+          data-testid="ai-openai-model"
+          value={modelChoice}
+          onChange={(e) => setModelChoice(e.target.value)}
+          className="mt-1"
+        >
+          <option value="">{t("settings.ai.modelOptionDefault")}</option>
+          {OPENAI_MODEL_PRESETS.map((m) => (
+            <option key={m} value={m}>
+              {m}
+            </option>
+          ))}
+          <option value={CUSTOM_MODEL_SENTINEL}>
+            {t("settings.ai.openai.modelOptionCustom")}
+          </option>
+        </NativeSelect>
+      </div>
+
+      {modelChoice === CUSTOM_MODEL_SENTINEL && (
+        <div>
+          <Label htmlFor="ai-openai-model-custom">
+            {t("settings.ai.openai.modelCustomLabel")}
+          </Label>
+          <Input
+            id="ai-openai-model-custom"
+            value={customModel}
+            onChange={(e) => setCustomModel(e.target.value)}
+            placeholder={t("settings.ai.openai.modelCustomPlaceholder")}
+            className="mt-1"
+          />
+        </div>
+      )}
+
+      <div>
+        <button
+          type="button"
+          onClick={() => setShowAdvanced((v) => !v)}
+          className="text-muted-foreground hover:text-foreground text-xs underline"
+        >
+          {showAdvanced
+            ? t("settings.ai.openai.hideAdvanced")
+            : t("settings.ai.openai.showAdvanced")}
+        </button>
+        {showAdvanced && (
+          <div className="mt-2 space-y-1">
+            <Label htmlFor="ai-openai-base-url">
+              {t("settings.ai.openai.baseUrlLabel")}
+            </Label>
+            <Input
+              id="ai-openai-base-url"
+              value={baseUrl}
+              onChange={(e) => setBaseUrl(e.target.value)}
+              placeholder={t("settings.ai.openai.baseUrlPlaceholder")}
+            />
+            <p className="text-muted-foreground text-xs">
+              {t("settings.ai.openai.baseUrlHelp")}
+            </p>
+          </div>
+        )}
+      </div>
+
+      <div className="flex flex-wrap gap-2">
+        <Button
+          size="sm"
+          onClick={() => saveMutation.mutate()}
+          disabled={saveMutation.isPending}
+        >
+          {saveMutation.isPending ? (
+            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+          ) : (
+            <Save className="h-4 w-4" />
+          )}
+          {t("settings.ai.saveCta")}
+        </Button>
+      </div>
+
+      {msg && (
+        <p className={`text-xs ${ok ? "text-success" : "text-destructive"}`}>
+          {msg}
+        </p>
+      )}
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/runtime-actions-row.tsx b/src/components/settings/ai/runtime-actions-row.tsx
new file mode 100644
index 000000000..265f1fc4b
--- /dev/null
+++ b/src/components/settings/ai/runtime-actions-row.tsx
@@ -0,0 +1,274 @@
+"use client";
+
+/* ────────────────────────────────────────────────────────────────
+ * Runtime actions — Test active provider, regenerate insights, raw-mode toggle.
+ * ──────────────────────────────────────────────────────────────── */
+
+import { useState } from "react";
+import { Loader2, RefreshCw, Sparkles } from "lucide-react";
+import { toast } from "sonner";
+
+import { Button } from "@/components/ui/button";
+import { Switch } from "@/components/ui/switch";
+import { apiFetchRaw, apiPut } from "@/lib/api/api-fetch";
+import { formatDateTime } from "@/lib/format";
+import { useTranslations } from "@/lib/i18n/context";
+
+import {
+  localiseTestReason,
+  type ProviderType,
+  type UserAIProvider,
+} from "./shared";
+
+export function RuntimeActionsRow({
+  provider,
+  userProvider,
+  canRegenerate,
+  privacyMode,
+  lastInsightAt,
+  onRegenerated,
+  onPrivacyChanged,
+}: {
+  provider: ProviderType;
+  userProvider: UserAIProvider | null | undefined;
+  canRegenerate: boolean;
+  privacyMode: string;
+  lastInsightAt: string | null;
+  onRegenerated: () => void;
+  onPrivacyChanged: () => void;
+}) {
+  const { t } = useTranslations();
+
+  const [testing, setTesting] = useState(false);
+  const [testMsg, setTestMsg] = useState<string | null>(null);
+  const [testOk, setTestOk] = useState(false);
+  const [regen, setRegen] = useState(false);
+  const [regenMsg, setRegenMsg] = useState<string | null>(null);
+  const [regenOk, setRegenOk] = useState(false);
+
+  async function runTest() {
+    setTesting(true);
+    setTestMsg(null);
+    try {
+      const res = await apiFetchRaw("/api/ai/test", { method: "POST" });
+      // Guard against a non-JSON body. A reverse proxy / Cloudflare can
+      // rewrite an origin error to its own HTML page; parsing that as JSON
+      // throws `Unexpected token '<'` (Safari: "did not match the
+      // expected pattern"). Show a clean message instead of leaking that.
+      const contentType = res.headers.get("content-type") ?? "";
+      if (!contentType.includes("application/json")) {
+        setTestOk(false);
+        setTestMsg(t("settings.ai.testUnexpectedResponse"));
+        return;
+      }
+      let json: {
+        data?: {
+          ok?: boolean;
+          providerType?: string;
+          model?: string;
+          reasonCode?: string;
+          reason?: string;
+        } | null;
+        error?: string | null;
+      };
+      try {
+        json = await res.json();
+      } catch {
+        setTestOk(false);
+        setTestMsg(t("settings.ai.testUnexpectedResponse"));
+        return;
+      }
+      // 4xx config errors still arrive via the error envelope.
+      if (!res.ok) {
+        setTestOk(false);
+        setTestMsg(
+          t("settings.ai.testFailedShort", {
+            message: json.error ?? `HTTP ${res.status}`,
+          }),
+        );
+        return;
+      }
+      // Provider-call failures now arrive as 200 + { ok:false, reasonCode }
+      // so the body is never rewritten by a proxy. Map the stable code to a
+      // localised string; fall back to the server's plain `reason` for any
+      // unmapped / legacy code, then to a generic message.
+      if (json.data && json.data.ok === false) {
+        setTestOk(false);
+        setTestMsg(
+          localiseTestReason(t, json.data.reasonCode, json.data.reason) ??
+            t("settings.ai.testFailedShort", { message: `HTTP ${res.status}` }),
+        );
+        return;
+      }
+      setTestOk(true);
+      setTestMsg(
+        t("settings.ai.testSuccess", {
+          provider: json.data?.providerType ?? "",
+          model: json.data?.model ?? "",
+        }),
+      );
+    } catch (e) {
+      setTestOk(false);
+      setTestMsg(
+        t("settings.ai.testFailedShort", {
+          message: e instanceof Error ? e.message : "fetch error",
+        }),
+      );
+    } finally {
+      setTesting(false);
+    }
+  }
+
+  async function regenerate() {
+    setRegen(true);
+    setRegenMsg(null);
+    try {
+      const res = await apiFetchRaw("/api/insights/generate", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ force: true }),
+      });
+      // Same defensive guard as the connection test: a proxy can rewrite
+      // a 5xx (e.g. all-providers-failed) to an HTML page, which would
+      // crash `res.json()` with `Unexpected token '<'`.
+      const contentType = res.headers.get("content-type") ?? "";
+      if (!contentType.includes("application/json")) {
+        setRegenOk(false);
+        setRegenMsg(
+          res.status === 429
+            ? t("settings.regenerateRateLimit")
+            : t("settings.ai.testUnexpectedResponse"),
+        );
+        return;
+      }
+      let json: { error?: string | null };
+      try {
+        json = await res.json();
+      } catch {
+        setRegenOk(false);
+        setRegenMsg(t("settings.ai.testUnexpectedResponse"));
+        return;
+      }
+      if (!res.ok) {
+        setRegenOk(false);
+        setRegenMsg(
+          res.status === 429
+            ? t("settings.regenerateRateLimit")
+            : json.error || t("settings.savingError"),
+        );
+        return;
+      }
+      setRegenOk(true);
+      setRegenMsg(t("settings.regenerateSuccess"));
+      onRegenerated();
+    } catch {
+      setRegenOk(false);
+      setRegenMsg(t("settings.savingError"));
+    } finally {
+      setRegen(false);
+    }
+  }
+
+  async function togglePrivacy() {
+    const next = privacyMode === "raw" ? "aggregated" : "raw";
+    // Privacy mode is a sensitive control: only reflect the new mode
+    // once the server confirms it. A swallowed 4xx/5xx would leave the
+    // UI showing a setting the server never accepted.
+    try {
+      await apiPut("/api/insights/settings", { privacyMode: next });
+      onPrivacyChanged();
+    } catch {
+      toast.error(t("settings.savingError"));
+    }
+  }
+
+  const lastInsightLine = lastInsightAt
+    ? `${t("settings.lastGeneratedAt")}: ${formatDateTime(lastInsightAt)}`
+    : null;
+
+  // Reserved for a future iteration that gates the Test button per
+  // provider (e.g. disable when admin-openai is selected and no admin
+  // key is present). For v1.4.16 the API decides.
+  void provider;
+  void userProvider;
+
+  return (
+    <div className="space-y-3">
+      <div className="flex flex-wrap items-center gap-2">
+        <Button
+          size="sm"
+          variant="outline"
+          onClick={runTest}
+          disabled={testing}
+          data-testid="ai-test-active-provider"
+        >
+          {testing ? (
+            <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+          ) : (
+            <Sparkles className="h-4 w-4" />
+          )}
+          {t("settings.ai.testProvider")}
+        </Button>
+        {canRegenerate && (
+          <Button
+            size="sm"
+            variant="outline"
+            onClick={regenerate}
+            disabled={regen}
+          >
+            {regen ? (
+              <Loader2 className="h-4 w-4 animate-spin motion-reduce:animate-none" />
+            ) : (
+              <RefreshCw className="h-4 w-4" />
+            )}
+            {t("settings.regenerateInsights")}
+          </Button>
+        )}
+        {lastInsightLine && (
+          <span className="text-muted-foreground text-xs">
+            {lastInsightLine}
+          </span>
+        )}
+      </div>
+
+      {canRegenerate && (
+        <div className="bg-muted/50 rounded-lg p-3">
+          <div className="flex items-center justify-between gap-4">
+            <div className="pr-2">
+              <p className="text-sm font-medium">{t("settings.rawData")}</p>
+              <p className="text-muted-foreground text-xs">
+                {privacyMode === "raw"
+                  ? t("settings.rawDataOnDescription")
+                  : t("settings.rawDataOffDescription")}
+              </p>
+            </div>
+            <Switch
+              checked={privacyMode === "raw"}
+              onCheckedChange={togglePrivacy}
+            />
+          </div>
+          {privacyMode === "raw" && (
+            <div className="bg-warning/15 text-warning mt-2 rounded-lg p-2 text-xs">
+              {t("settings.rawDataWarning")}
+            </div>
+          )}
+        </div>
+      )}
+
+      {testMsg && (
+        <p
+          className={`text-xs ${testOk ? "text-success" : "text-destructive"}`}
+        >
+          {testMsg}
+        </p>
+      )}
+      {regenMsg && (
+        <p
+          className={`text-xs ${regenOk ? "text-success" : "text-destructive"}`}
+        >
+          {regenMsg}
+        </p>
+      )}
+    </div>
+  );
+}
diff --git a/src/components/settings/ai/shared.ts b/src/components/settings/ai/shared.ts
new file mode 100644
index 000000000..4e1e796ce
--- /dev/null
+++ b/src/components/settings/ai/shared.ts
@@ -0,0 +1,142 @@
+/**
+ * Shared types, constants, and pure helpers for the Settings → AI
+ * provider components. Extracted from the former 2k-LOC
+ * `ai-section.tsx` monolith; one provider form per file lives next to
+ * this module under `src/components/settings/ai/`.
+ */
+
+export interface InsightsSettings {
+  codexStatus: string;
+  codexConnectedAt: string | null;
+  hasAdminKey: boolean;
+  /** True when the operator has set `CODEX_OAUTH_CLIENT_ID` on this
+   *  instance. The UI hides the "Connect with ChatGPT" button when
+   *  false to avoid the v1.4.2 dead-end where the click bounced the
+   *  user to chatgpt.com without any OAuth flow. */
+  codexOauthConfigured?: boolean;
+  privacyMode: string;
+  lastInsightAt: string | null;
+}
+
+export interface UserAIProvider {
+  provider: string | null;
+  model: string | null;
+  baseUrl: string | null;
+  hasAnthropicKey: boolean;
+  anthropicKeyPreview: string | null;
+  hasLocalKey: boolean;
+  hasOpenaiKey: boolean;
+  openaiKeyPreview: string | null;
+}
+
+/**
+ * v1.4.16 phase B2 — provider tags exposed to the UI. Mirrors
+ * `PROVIDER_CHAIN_TYPES` server-side; kept as a const-array here to
+ * avoid pulling a server-only module into the client bundle.
+ */
+export const PROVIDER_TYPES = [
+  "codex",
+  "openai",
+  "anthropic",
+  "local",
+  "admin-openai",
+] as const;
+export type ProviderType = (typeof PROVIDER_TYPES)[number];
+
+export interface ChainEntry {
+  providerType: ProviderType;
+  enabled: boolean;
+}
+
+export interface ProviderChainData {
+  activeProvider: ProviderType | null;
+  cachedActiveProvider: ProviderType | null;
+  configuredChain: {
+    providerType: ProviderType;
+    enabled: boolean;
+    available: boolean;
+  }[];
+}
+
+export const DEFAULT_CHAIN: readonly ChainEntry[] = [
+  { providerType: "codex", enabled: true },
+  { providerType: "openai", enabled: true },
+  { providerType: "anthropic", enabled: true },
+  { providerType: "local", enabled: true },
+  { providerType: "admin-openai", enabled: true },
+];
+
+/**
+ * OpenAI model presets — the wire-up keeps users out of the freetext
+ * box for the common case. The `__custom__` sentinel surfaces a
+ * freetext input so power users can target preview models or
+ * fine-tunes (e.g. `gpt-5`, which is admitted via the env override on
+ * the Codex backend but not yet a documented OpenAI model id).
+ */
+export const OPENAI_MODEL_PRESETS = [
+  "gpt-4o",
+  "gpt-4o-mini",
+  "gpt-4-turbo",
+] as const;
+export const ANTHROPIC_MODEL_PRESETS = [
+  "claude-sonnet-4-6",
+  "claude-opus-4-7",
+  "claude-haiku-4-5",
+  "claude-3-5-sonnet-latest",
+] as const;
+export const LOCAL_MODEL_PRESETS = [
+  "llama3.1:8b",
+  "llama3.1:70b",
+  "mistral",
+  "qwen2.5",
+] as const;
+export const CUSTOM_MODEL_SENTINEL = "__custom__";
+
+/**
+ * Map UI provider tag → the `aiProvider` enum understood by the
+ * legacy single-result `resolveProvider()` resolver. `codex` and
+ * `admin-openai` aren't user-level provider columns (they're handled
+ * by Codex OAuth + admin-key fallback), so they map to null and the
+ * legacy column is left blank.
+ */
+export function uiToLegacyProviderEnum(p: ProviderType): string | null {
+  switch (p) {
+    case "openai":
+      return "OPENAI";
+    case "anthropic":
+      return "ANTHROPIC";
+    case "local":
+      return "LOCAL";
+    case "codex":
+    case "admin-openai":
+    default:
+      return null;
+  }
+}
+
+// Map the connection-test failure category (a stable, secret-free code from
+// /api/ai/test) to a localised message. Falls back to the server's plain
+// English `reason` for any unmapped / legacy code so a German operator never
+// sees an untranslated sentence in the otherwise-localised Settings panel.
+export function localiseTestReason(
+  t: (key: string, params?: Record<string, string | number>) => string,
+  reasonCode: string | undefined,
+  reason: string | undefined,
+): string | undefined {
+  switch (reasonCode) {
+    case "credentials":
+      return t("settings.ai.testReasonCredentials");
+    case "rate_limited":
+      return t("settings.ai.testReasonRateLimited");
+    case "server_error":
+      return t("settings.ai.testReasonServerError");
+    case "unreachable":
+      return t("settings.ai.testReasonUnreachable");
+    default:
+      return reason;
+  }
+}
+
+export function isProviderType(v: string | null): v is ProviderType {
+  return v != null && (PROVIDER_TYPES as readonly string[]).includes(v);
+}
diff --git a/src/components/settings/api-section.tsx b/src/components/settings/api-section.tsx
index 4cfaacd3b..bfa732060 100644
--- a/src/components/settings/api-section.tsx
+++ b/src/components/settings/api-section.tsx
@@ -24,6 +24,7 @@ import { useAuth } from "@/hooks/use-auth";
 import { formatDate, formatDateTime } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface ApiTokenInfo {
   id: string;
@@ -168,9 +169,7 @@ function ApiTokensCard() {
   const { data: tokens } = useQuery({
     queryKey: queryKeys.tokens(),
     queryFn: async () => {
-      const res = await fetch("/api/tokens");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as ApiTokenInfo[];
+      return apiGet<ApiTokenInfo[]>("/api/tokens");
     },
     enabled: isAuthenticated,
   });
@@ -182,7 +181,7 @@ function ApiTokensCard() {
     setNewToken(null);
 
     try {
-      const res = await fetch("/api/tokens", {
+      const res = await apiFetchRaw("/api/tokens", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({ name: newName.trim() }),
@@ -218,7 +217,9 @@ function ApiTokensCard() {
 
   async function handleRevoke(tokenId: string) {
     try {
-      const res = await fetch(`/api/tokens/${tokenId}`, { method: "DELETE" });
+      const res = await apiFetchRaw(`/api/tokens/${tokenId}`, {
+        method: "DELETE",
+      });
       if (!res.ok) {
         toast.error(t("settings.tokenRevokeFailed"));
         return;
diff --git a/src/components/settings/coach-memory-section.tsx b/src/components/settings/coach-memory-section.tsx
index c341c1f08..78e61d55c 100644
--- a/src/components/settings/coach-memory-section.tsx
+++ b/src/components/settings/coach-memory-section.tsx
@@ -38,6 +38,7 @@ import { formatDateOrRelative } from "@/lib/format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
 import { toast } from "sonner";
+import { apiDelete, apiGet } from "@/lib/api/api-fetch";
 
 /** Closed enum mirrored from the server `CoachFact.category` column. */
 const FACT_CATEGORIES = [
@@ -66,12 +67,10 @@ const CATEGORY_LABEL_KEY: Record<FactCategory, string> = {
 };
 
 async function fetchFacts(): Promise<CoachFact[]> {
-  const res = await fetch("/api/insights/coach/facts");
-  if (!res.ok) {
-    throw new Error(`HTTP ${res.status}`);
-  }
-  const json = (await res.json()) as { data?: { facts?: CoachFact[] } };
-  return json.data?.facts ?? [];
+  const data = await apiGet<{ facts?: CoachFact[] } | undefined>(
+    "/api/insights/coach/facts",
+  );
+  return data?.facts ?? [];
 }
 
 export function CoachMemorySection({
@@ -91,13 +90,7 @@ export function CoachMemorySection({
   const forgetOne = useMutation({
     mutationKey: queryKeys.coachFacts(),
     mutationFn: async (id: string) => {
-      const res = await fetch(
-        `/api/insights/coach/facts/${encodeURIComponent(id)}`,
-        { method: "DELETE" },
-      );
-      if (!res.ok) {
-        throw new Error(`HTTP ${res.status}`);
-      }
+      await apiDelete(`/api/insights/coach/facts/${encodeURIComponent(id)}`);
       return id;
     },
     onSuccess: () => {
@@ -112,14 +105,10 @@ export function CoachMemorySection({
   const forgetAll = useMutation({
     mutationKey: queryKeys.coachFacts(),
     mutationFn: async () => {
-      const res = await fetch("/api/insights/coach/facts", {
-        method: "DELETE",
-      });
-      if (!res.ok) {
-        throw new Error(`HTTP ${res.status}`);
-      }
-      const json = (await res.json()) as { data?: { cleared?: number } };
-      return json.data?.cleared ?? 0;
+      const data = await apiDelete<{ cleared?: number } | undefined>(
+        "/api/insights/coach/facts",
+      );
+      return data?.cleared ?? 0;
     },
     onSuccess: (cleared) => {
       toast.success(
diff --git a/src/components/settings/coach-nudge-card.tsx b/src/components/settings/coach-nudge-card.tsx
index 7e8e83fff..fa3edba3a 100644
--- a/src/components/settings/coach-nudge-card.tsx
+++ b/src/components/settings/coach-nudge-card.tsx
@@ -18,6 +18,7 @@ import { Switch } from "@/components/ui/switch";
 import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface NotificationPrefsShape {
   coach: { nudgesEnabled: boolean };
@@ -60,9 +61,7 @@ export function CoachNudgeCard({
   const { data: prefs } = useQuery({
     queryKey: queryKeys.authNotificationPrefs(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/me/notification-prefs");
-      if (!res.ok) throw new Error("Failed to load notification prefs");
-      return (await res.json()).data as NotificationPrefsShape;
+      return apiGet<NotificationPrefsShape>("/api/auth/me/notification-prefs");
     },
     enabled: isAuthenticated,
   });
@@ -79,7 +78,7 @@ export function CoachNudgeCard({
       clearTimerRef.current = null;
     }
 
-    const res = await fetch("/api/auth/me/notification-prefs", {
+    const res = await apiFetchRaw("/api/auth/me/notification-prefs", {
       method: "PATCH",
       headers: { "Content-Type": "application/json" },
       body: JSON.stringify({ coach: { nudgesEnabled: next } }),
diff --git a/src/components/settings/cycle-tracking-card.tsx b/src/components/settings/cycle-tracking-card.tsx
index b6aab2f7f..575f019ba 100644
--- a/src/components/settings/cycle-tracking-card.tsx
+++ b/src/components/settings/cycle-tracking-card.tsx
@@ -10,6 +10,7 @@ import { Switch } from "@/components/ui/switch";
 import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet, apiPatch } from "@/lib/api/api-fetch";
 
 /**
  * v1.15.0 — the cycle-tracking enable on-ramp.
@@ -39,21 +40,13 @@ export function CycleTrackingCard({
     queryKey: queryKeys.cyclePrefs(),
     enabled: isAuthenticated,
     queryFn: async () => {
-      const res = await fetch("/api/auth/me/cycle-prefs");
-      if (!res.ok) throw new Error(`Request failed: ${res.status}`);
-      return (await res.json()).data as CyclePrefsShape;
+      return apiGet<CyclePrefsShape>("/api/auth/me/cycle-prefs");
     },
   });
 
   const toggle = useMutation({
     mutationFn: async (enabled: boolean) => {
-      const res = await fetch("/api/auth/me/cycle-prefs", {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ enabled }),
-      });
-      if (!res.ok) throw new Error(`Request failed: ${res.status}`);
-      return (await res.json()).data as CyclePrefsShape;
+      return apiPatch<CyclePrefsShape>("/api/auth/me/cycle-prefs", { enabled });
     },
     onSuccess: () => {
       void queryClient.invalidateQueries({ queryKey: queryKeys.cyclePrefs() });
diff --git a/src/components/settings/dashboard-layout-section.tsx b/src/components/settings/dashboard-layout-section.tsx
index 0e9afd854..c375bed78 100644
--- a/src/components/settings/dashboard-layout-section.tsx
+++ b/src/components/settings/dashboard-layout-section.tsx
@@ -48,6 +48,7 @@ import {
   SelectTrigger,
   SelectValue,
 } from "@/components/ui/select";
+import { apiDelete, apiGet, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * v1.4.47 W4 — pure reorder helper shared by the arrow buttons and the
@@ -171,10 +172,7 @@ export function DashboardLayoutSection({ id }: { id: string }) {
   const { data: remote, isLoading } = useQuery({
     queryKey: queryKeys.dashboardWidgets(),
     queryFn: async () => {
-      const res = await fetch("/api/dashboard/widgets");
-      if (!res.ok) throw new Error("failed");
-      const json = await res.json();
-      return json.data as DashboardLayout;
+      return apiGet<DashboardLayout>("/api/dashboard/widgets");
     },
   });
 
@@ -187,13 +185,7 @@ export function DashboardLayoutSection({ id }: { id: string }) {
 
   const saveMutation = useMutation({
     mutationFn: async (next: DashboardLayout) => {
-      const res = await fetch("/api/dashboard/widgets", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(next),
-      });
-      if (!res.ok) throw new Error("save failed");
-      return (await res.json()).data as DashboardLayout;
+      return apiPut<DashboardLayout>("/api/dashboard/widgets", next);
     },
     onSuccess: (saved) => {
       queryClient.setQueryData(queryKeys.dashboardWidgets(), saved);
@@ -205,9 +197,7 @@ export function DashboardLayoutSection({ id }: { id: string }) {
 
   const resetMutation = useMutation({
     mutationFn: async () => {
-      const res = await fetch("/api/dashboard/widgets", { method: "DELETE" });
-      if (!res.ok) throw new Error("reset failed");
-      return (await res.json()).data as DashboardLayout;
+      return apiDelete<DashboardLayout>("/api/dashboard/widgets");
     },
     onSuccess: (saved) => {
       queryClient.setQueryData(queryKeys.dashboardWidgets(), saved);
@@ -230,7 +220,7 @@ export function DashboardLayoutSection({ id }: { id: string }) {
    * v1.4.15 Fix 5 — independent toggle for the *strip tile* (the upper
    * row of trend cards). Until v1.4.14 a single switch controlled both
    * the tile AND the chart for the same metric, which the maintainer found too
-   * coarse: he wanted a chart visible without the tile (for metrics he
+   * coarse: they wanted a chart visible without the tile (for metrics they
    * tracks without wanting the at-a-glance number) or vice versa.
    */
   function toggleTile(widgetId: DashboardWidgetId, tileVisible: boolean) {
diff --git a/src/components/settings/export-section.tsx b/src/components/settings/export-section.tsx
index 68da3f3a6..7652965e6 100644
--- a/src/components/settings/export-section.tsx
+++ b/src/components/settings/export-section.tsx
@@ -46,6 +46,7 @@ import { HealthRecordExportPanel } from "@/components/settings/health-record-exp
 import { ImportPanel } from "@/components/settings/import-panel";
 import { queryKeys } from "@/lib/query-keys";
 import { useTranslations } from "@/lib/i18n/context";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 type ExportFormat = "CSV" | "JSON" | "FHIR";
 
@@ -504,11 +505,7 @@ function CycleExportCard() {
   const prefsQuery = useQuery({
     queryKey: queryKeys.cyclePrefs(),
     queryFn: async (): Promise<{ cycleTrackingEnabled: boolean }> => {
-      const res = await fetch("/api/auth/me/cycle-prefs", {
-        credentials: "include",
-      });
-      if (!res.ok) throw new Error(`prefs-${res.status}`);
-      return (await res.json()).data as { cycleTrackingEnabled: boolean };
+      return apiGet<{ cycleTrackingEnabled: boolean }>("/api/auth/me/cycle-prefs", { credentials: "include" });
     },
     staleTime: 5 * 60 * 1000,
   });
@@ -521,7 +518,7 @@ function CycleExportCard() {
     setBusy(true);
     setError(null);
     try {
-      const res = await fetch("/api/export/health-record", {
+      const res = await apiFetchRaw("/api/export/health-record", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         credentials: "include",
diff --git a/src/components/settings/health-record-export-panel.tsx b/src/components/settings/health-record-export-panel.tsx
index 9da103dea..dd1a5a25b 100644
--- a/src/components/settings/health-record-export-panel.tsx
+++ b/src/components/settings/health-record-export-panel.tsx
@@ -30,6 +30,7 @@ import { Input } from "@/components/ui/input";
 import { NativeSelect } from "@/components/ui/native-select";
 import { Switch } from "@/components/ui/switch";
 import { useRovingRadioGroup } from "@/hooks/use-roving-radio-group";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
 import { useTranslations } from "@/lib/i18n/context";
 import { cn } from "@/lib/utils";
 
@@ -146,7 +147,7 @@ export function HealthRecordExportPanel() {
     setBusy(true);
     setError(null);
     try {
-      const res = await fetch("/api/export/health-record", {
+      const res = await apiFetchRaw("/api/export/health-record", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         credentials: "include",
diff --git a/src/components/settings/import-panel.tsx b/src/components/settings/import-panel.tsx
index 5310b16cd..3a9fba2e3 100644
--- a/src/components/settings/import-panel.tsx
+++ b/src/components/settings/import-panel.tsx
@@ -43,6 +43,7 @@ import { Textarea } from "@/components/ui/textarea";
 import { queryKeys } from "@/lib/query-keys";
 import { useTranslations } from "@/lib/i18n/context";
 import { cn } from "@/lib/utils";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 // ─────────────────────────── Section wrapper ───────────────────────────
 
@@ -143,14 +144,7 @@ function AppleHealthImportCard() {
       return 2000;
     },
     queryFn: async (): Promise<JobStatus> => {
-      const res = await fetch(
-        `/api/import/apple-health-export/${jobId}/status`,
-        { credentials: "include" },
-      );
-      if (!res.ok) {
-        throw new Error(`status-${res.status}`);
-      }
-      return (await res.json()).data as JobStatus;
+      return apiGet<JobStatus>(`/api/import/apple-health-export/${jobId}/status`, { credentials: "include" });
     },
   });
 
@@ -162,7 +156,7 @@ function AppleHealthImportCard() {
       try {
         const form = new FormData();
         form.append("file", file);
-        const res = await fetch("/api/import/apple-health-export", {
+        const res = await apiFetchRaw("/api/import/apple-health-export", {
           method: "POST",
           credentials: "include",
           body: form,
@@ -481,7 +475,7 @@ function JsonImportCard() {
     const payload = parsed.value;
     setBusy(true);
     try {
-      const res = await fetch("/api/import", {
+      const res = await apiFetchRaw("/api/import", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         credentials: "include",
diff --git a/src/components/settings/injection-sites-card.tsx b/src/components/settings/injection-sites-card.tsx
index 18a8cb809..89549d7d4 100644
--- a/src/components/settings/injection-sites-card.tsx
+++ b/src/components/settings/injection-sites-card.tsx
@@ -12,6 +12,7 @@ import {
   describeInjectionSite,
   type InjectionSiteKey,
 } from "@/lib/medications/injection-sites";
+import { apiFetchRaw, apiPatch } from "@/lib/api/api-fetch";
 
 /**
  * v1.8.5 — Settings → global injection-site exclusion.
@@ -33,7 +34,7 @@ export function InjectionSitesCard({
   const { data } = useQuery({
     queryKey: queryKeys.injectionSitePrefs(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/me/injection-site-prefs");
+      const res = await apiFetchRaw("/api/auth/me/injection-site-prefs");
       if (!res.ok) return [] as InjectionSiteKey[];
       const json = await res.json();
       return (json.data?.globalExcludedInjectionSites ??
@@ -46,12 +47,7 @@ export function InjectionSitesCard({
 
   const mutation = useMutation({
     mutationFn: async (next: InjectionSiteKey[]) => {
-      const res = await fetch("/api/auth/me/injection-site-prefs", {
-        method: "PATCH",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ globalExcludedInjectionSites: next }),
-      });
-      if (!res.ok) throw new Error("patch_failed");
+      await apiPatch("/api/auth/me/injection-site-prefs", { globalExcludedInjectionSites: next });
     },
     onSuccess: () => {
       void queryClient.invalidateQueries({
diff --git a/src/components/settings/insights-pill-order-section.tsx b/src/components/settings/insights-pill-order-section.tsx
index 14004bf24..c4bf81792 100644
--- a/src/components/settings/insights-pill-order-section.tsx
+++ b/src/components/settings/insights-pill-order-section.tsx
@@ -42,6 +42,7 @@ import {
   type ManagerGroup,
 } from "@/lib/insights/sub-page-metric";
 import { SUB_PAGE_TABS } from "@/components/insights/insights-tab-strip";
+import { apiPut } from "@/lib/api/api-fetch";
 
 /**
  * v1.15.18 — dedicated pill-sort control for the Insights settings section.
@@ -123,19 +124,13 @@ export function InsightsPillOrderSection({ id }: { id?: string }) {
 
   const saveMutation = useMutation({
     mutationFn: async (tiles: InsightsTileConfig[]) => {
-      const res = await fetch("/api/insights/layout", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
+      return apiPut<InsightsLayout>("/api/insights/layout", {
           version: 2,
           // Preserve the overview section order/visibility verbatim — this
           // surface owns the PILL order only.
           sections: layout.sections,
           tiles,
-        }),
-      });
-      if (!res.ok) throw new Error("save failed");
-      return (await res.json()).data as InsightsLayout;
+        });
     },
     onSuccess: (saved) => {
       queryClient.setQueryData(queryKeys.insightsLayout(), saved);
diff --git a/src/components/settings/integrations-section.tsx b/src/components/settings/integrations-section.tsx
index eff568b5c..3a8548709 100644
--- a/src/components/settings/integrations-section.tsx
+++ b/src/components/settings/integrations-section.tsx
@@ -3,175 +3,19 @@
 import { useEffect, useState } from "react";
 import Link from "next/link";
 import { useRouter } from "next/navigation";
-import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+import { useQueryClient } from "@tanstack/react-query";
 import { toast } from "sonner";
-import {
-  Activity,
-  AlertCircle,
-  HeartPulse,
-  Link2,
-  Loader2,
-  RefreshCw,
-  Save,
-  Unlink,
-} from "lucide-react";
 
+import { FitbitCard } from "@/components/settings/integrations/fitbit-card";
 import {
-  AlertDialog,
-  AlertDialogAction,
-  AlertDialogCancel,
-  AlertDialogContent,
-  AlertDialogDescription,
-  AlertDialogFooter,
-  AlertDialogHeader,
-  AlertDialogTitle,
-  AlertDialogTrigger,
-} from "@/components/ui/alert-dialog";
-import { Badge } from "@/components/ui/badge";
-import { Button } from "@/components/ui/button";
-import { Input } from "@/components/ui/input";
-import { Label } from "@/components/ui/label";
-import { PasswordInput } from "@/components/ui/password-input";
-import { TestConnectionButton } from "@/components/settings/test-connection-button";
-import { SettingsCardHeader } from "@/components/settings/_card-header";
-import { IntegrationStatusPill } from "@/components/settings/integration-status-pill";
-import type { IntegrationPillState } from "@/components/settings/integration-status-pill";
+  pickStatus,
+  useIntegrationStatuses,
+} from "@/components/settings/integrations/shared";
+import { WhoopCard } from "@/components/settings/integrations/whoop-card";
+import { WithingsCard } from "@/components/settings/integrations/withings-card";
 import { useAuth } from "@/hooks/use-auth";
 import { useTranslations } from "@/lib/i18n/context";
-import {
-  invalidateKeys,
-  measurementDependentKeys,
-  queryKeys,
-} from "@/lib/query-keys";
-
-// v1.4.15 Phase B2: shared status payload for both integration cards.
-// v1.4.19 Phase A5: the redundant in-card status banner is gone — the
-// IntegrationStatusPill now owns state + last-sync presentation, and
-// the actionable error message is shown inline above the action row.
-type IntegrationKey = "withings" | "whoop" | "fitbit" | "moodlog";
-type IntegrationState =
-  | "connected"
-  | "error_transient"
-  | "error_reauth"
-  | "disconnected"
-  | "parked";
-
-interface IntegrationStatusViewModel {
-  integration: IntegrationKey;
-  state: IntegrationState;
-  lastSuccessAt: string | null;
-  lastAttemptAt: string | null;
-  lastError: string | null;
-  consecutiveFailuresByKind?: {
-    transient: number;
-    reauth_required: number;
-    persistent: number;
-  } | null;
-  configured?: boolean;
-  connected?: boolean;
-  connectedAt?: string | null;
-  legacyLastSyncedAt?: string | null;
-  tokenExpiresAt?: string | null;
-  tokenExpired?: boolean | null;
-  enabled?: boolean;
-  // Withings activity-scope reconnect banner.
-  scope?: string | null;
-  hasActivityScope?: boolean;
-  // WHOOP / Fitbit backfill-in-progress note.
-  backfillCompleted?: boolean | null;
-  // moodLog webhook secret + entry count.
-  webhookSecret?: string | null;
-  entryCount?: number;
-}
-
-interface IntegrationStatusEnvelope {
-  threshold: number;
-  integrations: IntegrationStatusViewModel[];
-}
-
-/**
- * Shared status fetch for the Settings → Integrations card. Returns
- * the per-integration view-model AND the global threshold so the
- * "{n}/{threshold} consecutive failures" string in the UI is single-
- * sourced from the server.
- */
-function useIntegrationStatuses(enabled: boolean) {
-  return useQuery({
-    queryKey: queryKeys.integrationsStatus(),
-    queryFn: async () => {
-      const res = await fetch("/api/integrations/status");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as IntegrationStatusEnvelope;
-    },
-    enabled,
-    refetchOnWindowFocus: true,
-  });
-}
-
-function pickStatus(
-  envelope: IntegrationStatusEnvelope | undefined,
-  integration: IntegrationKey,
-): IntegrationStatusViewModel | undefined {
-  return envelope?.integrations.find((i) => i.integration === integration);
-}
-
-/**
- * Collapse the API's five-state machine into the four states the
- * pill UI cares about. `error_transient` and `error_reauth` both
- * surface as the same "Error — reconnect" pill, the actionable
- * difference (whether the user must reconnect vs wait for the next
- * retry) is conveyed via the inline error text underneath. `parked`
- * (v1.4.43 W14) is its own pill state — the integration has been
- * disabled after 24h of persistent failures and needs an explicit
- * "Wieder verbinden" click to resume.
- */
-function pillStateFor(
-  status: IntegrationStatusViewModel | undefined,
-): IntegrationPillState {
-  if (!status) return "disconnected";
-  switch (status.state) {
-    case "connected":
-      return "connected";
-    case "error_transient":
-      // v1.4.43 W4 H3 — a `persistent` failure-kind streak (Withings
-      // rate-limit 601 / contract-mismatch 293/294) maps to the same
-      // `error_transient` DB state as a normal retryable failure but
-      // tells the user a different story: the access token still
-      // works, the upstream is responding with a non-recoverable
-      // status. Surfacing it as a "warning" pill (orange) instead of
-      // the red "Fehler — neu verbinden" stops the user from clicking
-      // reconnect ten times when reconnect can't fix it.
-      if ((status.consecutiveFailuresByKind?.persistent ?? 0) > 0) {
-        return "warning";
-      }
-      return "error";
-    case "error_reauth":
-      return "error";
-    case "parked":
-      return "parked";
-    case "disconnected":
-      return "disconnected";
-  }
-}
-
-/**
- * Inline actionable error message that surfaces under the pill when a
- * sync attempt failed. The pill conveys "something is wrong"; this
- * line tells the user *what* is wrong so they can act on it. Keeping
- * it deliberately small (one icon + one line) so it doesn't recreate
- * the v1.4.18 redundant banner the maintainer removed.
- */
-function IntegrationErrorMessage({ message }: { message: string }) {
-  return (
-    <p
-      data-testid="integration-error-message"
-      className="text-destructive flex items-start gap-1.5 text-sm"
-    >
-      <AlertCircle className="mt-0.5 h-3.5 w-3.5 shrink-0" />
-      <span className="min-w-0 break-words">{message}</span>
-    </p>
-  );
-}
+import { queryKeys } from "@/lib/query-keys";
 
 /**
  * The Withings OAuth callback (`/api/withings/callback`) redirects back
@@ -286,1340 +130,3 @@ export function IntegrationsSection() {
     </section>
   );
 }
-
-function WithingsCard({
-  viewModel,
-}: {
-  viewModel: IntegrationStatusViewModel | undefined;
-}) {
-  const { t } = useTranslations();
-  const [syncing, setSyncing] = useState(false);
-  const [syncMsg, setSyncMsg] = useState<string | null>(null);
-  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
-    null,
-  );
-  const [clientId, setClientId] = useState("");
-  const [clientSecret, setClientSecret] = useState("");
-  const [credsSaving, setCredsSaving] = useState(false);
-  const [credsMsg, setCredsMsg] = useState<string | null>(null);
-  const [credsMsgType, setCredsMsgType] = useState<"success" | "error" | null>(
-    null,
-  );
-  const queryClient = useQueryClient();
-
-  // v1.12.1 — the Withings status is read off the consolidated
-  // /api/integrations/status envelope (the `viewModel` prop). The
-  // per-card /api/withings/status round-trip is gone; the envelope
-  // carries every field this card renders (connected / configured /
-  // last-sync / activity scope).
-  const status = viewModel;
-
-  const disconnect = useMutation({
-    mutationFn: async () => {
-      const res = await fetch("/api/withings/disconnect", { method: "POST" });
-      if (!res.ok) throw new Error("Failed");
-    },
-    onSuccess: () => {
-      queryClient.invalidateQueries({ queryKey: queryKeys.withings() });
-      queryClient.invalidateQueries({
-        queryKey: queryKeys.integrationsStatus(),
-      });
-    },
-  });
-
-  // v1.4.43 W14 — clear a parked integration via the resume endpoint.
-  // The CTA is rendered inside the parked banner below; success
-  // invalidates both the per-card status (so the pill flips back to
-  // connected immediately) and the cross-integration envelope (so any
-  // other view picks up the change on its next focus).
-  const resume = useMutation({
-    mutationFn: async () => {
-      const res = await fetch("/api/integrations/withings/resume", {
-        method: "POST",
-      });
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as {
-        resumed: boolean;
-        wasParked: boolean;
-      };
-    },
-    onSuccess: () => {
-      queryClient.invalidateQueries({ queryKey: queryKeys.withings() });
-      queryClient.invalidateQueries({
-        queryKey: queryKeys.integrationsStatus(),
-      });
-    },
-  });
-
-  async function handleSync(fullSync = false) {
-    setSyncing(true);
-    setSyncMsg(null);
-    setSyncMsgType(null);
-    try {
-      const res = await fetch("/api/withings/sync", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ fullSync }),
-      });
-      const json = await res.json();
-      if (res.ok) {
-        setSyncMsg(
-          fullSync
-            ? t("settings.withingsFullSyncResult", {
-                count: json.data.imported,
-              })
-            : t("settings.withingsSyncResult", { count: json.data.imported }),
-        );
-        setSyncMsgType("success");
-        void invalidateKeys(queryClient, measurementDependentKeys);
-        queryClient.invalidateQueries({
-          queryKey: queryKeys.integrationsStatus(),
-        });
-      } else {
-        setSyncMsg(json.error || t("settings.withingsSyncFailed"));
-        setSyncMsgType("error");
-      }
-    } catch {
-      setSyncMsg(t("settings.withingsSyncFailed"));
-      setSyncMsgType("error");
-    } finally {
-      setSyncing(false);
-    }
-  }
-
-  async function handleSaveCredentials(e: React.FormEvent) {
-    e.preventDefault();
-    setCredsSaving(true);
-    setCredsMsg(null);
-    setCredsMsgType(null);
-
-    try {
-      const res = await fetch("/api/withings/credentials", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          clientId: clientId.trim(),
-          clientSecret: clientSecret.trim(),
-        }),
-      });
-
-      if (res.ok) {
-        setCredsMsg(t("settings.withingsCredentialsSaved"));
-        setCredsMsgType("success");
-        setClientId("");
-        setClientSecret("");
-        queryClient.invalidateQueries({ queryKey: queryKeys.withings() });
-      } else {
-        try {
-          const json = await res.json();
-          setCredsMsg(json.error || t("settings.savingError"));
-        } catch {
-          setCredsMsg(t("settings.savingError"));
-        }
-        setCredsMsgType("error");
-      }
-    } catch {
-      setCredsMsg(t("common.networkError"));
-      setCredsMsgType("error");
-    }
-    setCredsSaving(false);
-  }
-
-  // The pill state derives from the cross-integration status
-  // envelope. `legacyLastSyncedAt` is the connection row's own
-  // last-sync timestamp (carried in the same envelope) so the pill
-  // still paints a fresh "X min ago" right after a manual sync once
-  // the envelope refetches. When the envelope hasn't answered yet we
-  // fall back to "disconnected" so the card never renders status-less.
-  const pillState: IntegrationPillState = status?.connected
-    ? pillStateFor(viewModel)
-    : "disconnected";
-  const pillLastSyncAt =
-    status?.legacyLastSyncedAt ?? viewModel?.lastSuccessAt ?? null;
-  // v1.4.43 W14 — `parked` and `error` both want the underlying error
-  // message surfaced under the pill (the pill says "what" — the
-  // message says "why"). Other states leave the inline line off.
-  const errorMessage =
-    (pillState === "error" || pillState === "parked") && viewModel?.lastError
-      ? viewModel.lastError
-      : null;
-
-  return (
-    <div className="bg-card border-border rounded-xl border p-6">
-      <SettingsCardHeader
-        icon={Link2}
-        title={t("settings.withings")}
-        description={t("settings.withingsDescription")}
-        status={
-          <IntegrationStatusPill
-            state={pillState}
-            lastSyncAt={pillLastSyncAt}
-          />
-        }
-      />
-
-      <hr
-        data-testid="integration-card-divider"
-        className="border-border/60 mt-4"
-      />
-
-      <div className="mt-4 space-y-4 pl-7">
-        {errorMessage && <IntegrationErrorMessage message={errorMessage} />}
-        {/* v1.4.25 W5d — Withings activity-scope reconnect banner.
-            Only paints when (a) the user has an active Withings
-            connection (so the credentials are already saved + a token
-            exists) AND (b) the persisted scope is missing
-            `user.activity`. Reconnecting takes the user through the
-            standard /api/withings/connect → Withings → callback flow;
-            the callback persists the upgraded scope and the banner
-            vanishes on the next status poll. */}
-        {status?.connected && status?.hasActivityScope === false && (
-          <a
-            href="/api/withings/connect"
-            data-testid="withings-reconnect-banner"
-            className="border-warning/30 bg-warning/10 text-warning-foreground hover:bg-warning/20 block rounded-md border px-3 py-2 text-sm transition-colors"
-          >
-            <span className="font-medium">
-              {t("settings.integrations.withings.reconnect.banner.title")}
-            </span>
-            <span className="text-muted-foreground block text-xs">
-              {t("settings.integrations.withings.reconnect.banner.body")}
-            </span>
-            <span className="text-primary mt-1 inline-block text-xs font-medium">
-              {t("settings.integrations.withings.reconnect.banner.action")}
-              {" →"}
-            </span>
-          </a>
-        )}
-        {/* v1.4.43 W14 — parked-integration resume CTA. Surfaces only
-            when the row state is `parked` (>24h of persistent
-            failures). The button POSTs to /api/integrations/withings/
-            resume which calls `resumeIntegrationFromPark`; on success
-            the per-card status invalidates and the pill flips back to
-            connected without a page refresh. The button is the
-            primary action the user can take from this card — wider
-            tap target than the inline action row so it's reachable
-            on a Pixel 5 viewport. */}
-        {pillState === "parked" && (
-          <div
-            data-testid="withings-parked-banner"
-            className="border-warning/30 bg-warning/10 flex flex-wrap items-center justify-between gap-2 rounded-md border px-3 py-2 text-sm"
-          >
-            <span className="text-warning min-w-0 text-xs break-words">
-              {t("settings.integrationPill.parkedReconnect")}
-            </span>
-            <Button
-              type="button"
-              size="sm"
-              variant="outline"
-              onClick={() => resume.mutate()}
-              disabled={resume.isPending}
-              data-testid="withings-resume-button"
-              className="min-h-11"
-            >
-              {resume.isPending ? (
-                <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-              ) : (
-                <Link2 className="h-3.5 w-3.5" />
-              )}
-              {t("settings.integrationPill.resumeCta")}
-            </Button>
-          </div>
-        )}
-        {resume.isError && (
-          <p
-            role="alert"
-            className="text-destructive text-sm"
-            data-testid="withings-resume-error"
-          >
-            {t("settings.integrationPill.resumeError")}
-          </p>
-        )}
-        {resume.isSuccess && resume.data?.wasParked && (
-          <p
-            role="status"
-            className="text-success text-xs"
-            data-testid="withings-resume-success"
-          >
-            {t("settings.integrationPill.resumeSuccess")}
-          </p>
-        )}
-        <div className="space-y-3">
-          <h3 className="text-sm font-semibold">
-            {t("settings.withingsCredentials")}
-          </h3>
-          <form onSubmit={handleSaveCredentials} className="space-y-3">
-            {/* v1.4.27 MB7 / CF-53 — the credentials grid drops from
-                a 3-column row (client-id / secret / save) to a
-                2-column row of inputs at `sm:`, with the Save button
-                lifted out into its own row below. The previous
-                "invisible Label" hack to align the button with the
-                input baselines fell apart on Galaxy Fold; lifting
-                the button into a dedicated `flex justify-end` row
-                gives it consistent placement on every viewport and
-                lets the input pair span the full width. */}
-            <div className="grid gap-3 sm:grid-cols-2">
-              <div className="space-y-1.5">
-                <Label htmlFor="w-clientid">
-                  {t("settings.withingsClientId")}
-                </Label>
-                <Input
-                  id="w-clientid"
-                  value={clientId}
-                  onChange={(e) => setClientId(e.target.value)}
-                  placeholder={
-                    status?.configured
-                      ? t("settings.withingsCredentialsSavedPlaceholder")
-                      : t("settings.withingsClientId")
-                  }
-                  maxLength={200}
-                  autoComplete="off"
-                  inputMode="text"
-                  spellCheck={false}
-                  autoCapitalize="none"
-                  enterKeyHint="next"
-                />
-              </div>
-              <div className="space-y-1.5">
-                <Label htmlFor="w-secret">
-                  {t("settings.withingsClientSecret")}
-                </Label>
-                <PasswordInput
-                  id="w-secret"
-                  value={clientSecret}
-                  onChange={(e) => setClientSecret(e.target.value)}
-                  placeholder={
-                    status?.configured
-                      ? t("settings.withingsCredentialsSavedPlaceholderSecret")
-                      : t("settings.withingsClientSecret")
-                  }
-                  maxLength={200}
-                  autoComplete="off"
-                  inputMode="text"
-                  spellCheck={false}
-                  autoCapitalize="none"
-                  enterKeyHint="done"
-                />
-              </div>
-            </div>
-            <div className="flex justify-end">
-              <Button
-                type="submit"
-                variant="outline"
-                size="sm"
-                className="min-h-11 w-full sm:w-auto"
-                disabled={
-                  credsSaving || !clientId.trim() || !clientSecret.trim()
-                }
-              >
-                {credsSaving ? (
-                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                ) : (
-                  <Save className="h-3.5 w-3.5" />
-                )}
-                {t("settings.withingsSaveCredentials")}
-              </Button>
-            </div>
-            {credsMsg && (
-              <p
-                role="alert"
-                className={`text-sm ${credsMsgType === "success" ? "text-success" : "text-destructive"}`}
-              >
-                {credsMsg}
-              </p>
-            )}
-          </form>
-        </div>
-
-        {status?.connected ? (
-          <>
-            {/* v1.4.27 MB7 / CF-57 — the action row already wraps via
-                `flex-wrap`, but on Pixel 5 the four AlertDialog +
-                test-connection triggers each took a fractional slot
-                that read jagged. Force each button to a `min-w-[10rem]`
-                on `<sm` so they stack two per row at most and fill
-                their column cleanly. Tablet+ keeps the inline row. */}
-            <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
-              <Button
-                variant="outline"
-                size="sm"
-                className="min-h-11"
-                onClick={() => handleSync(false)}
-                disabled={syncing}
-              >
-                {syncing ? (
-                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                ) : (
-                  <RefreshCw className="h-3.5 w-3.5" />
-                )}
-                {t("settings.withingsSync")}
-              </Button>
-              <AlertDialog>
-                <AlertDialogTrigger asChild>
-                  <Button
-                    variant="outline"
-                    size="sm"
-                    className="min-h-11"
-                    disabled={syncing}
-                  >
-                    {syncing ? (
-                      <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                    ) : (
-                      <RefreshCw className="h-3.5 w-3.5" />
-                    )}
-                    {t("settings.withingsFullSync")}
-                  </Button>
-                </AlertDialogTrigger>
-                <AlertDialogContent>
-                  <AlertDialogHeader>
-                    <AlertDialogTitle>
-                      {t("settings.withingsFullSyncTitle")}
-                    </AlertDialogTitle>
-                    <AlertDialogDescription>
-                      {t("settings.withingsFullSyncDescription")}
-                    </AlertDialogDescription>
-                  </AlertDialogHeader>
-                  <AlertDialogFooter>
-                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
-                    <AlertDialogAction onClick={() => handleSync(true)}>
-                      {t("settings.withingsSynchronize")}
-                    </AlertDialogAction>
-                  </AlertDialogFooter>
-                </AlertDialogContent>
-              </AlertDialog>
-              <TestConnectionButton
-                endpoint="/api/integrations/withings/test"
-                disabled={!status?.connected}
-              />
-              <AlertDialog>
-                <AlertDialogTrigger asChild>
-                  <Button
-                    variant="outline"
-                    size="sm"
-                    className="text-destructive min-h-11"
-                  >
-                    <Unlink className="h-3.5 w-3.5" />
-                    {t("settings.withingsDisconnect")}
-                  </Button>
-                </AlertDialogTrigger>
-                <AlertDialogContent>
-                  <AlertDialogHeader>
-                    <AlertDialogTitle>
-                      {t("settings.withingsDisconnectTitle")}
-                    </AlertDialogTitle>
-                    <AlertDialogDescription>
-                      {t("settings.withingsDisconnectDescription")}
-                    </AlertDialogDescription>
-                  </AlertDialogHeader>
-                  <AlertDialogFooter>
-                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
-                    <AlertDialogAction
-                      variant="destructive"
-                      onClick={() => disconnect.mutate()}
-                    >
-                      {t("settings.withingsDisconnect")}
-                    </AlertDialogAction>
-                  </AlertDialogFooter>
-                </AlertDialogContent>
-              </AlertDialog>
-            </div>
-            {syncMsg && (
-              <p
-                role="alert"
-                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
-              >
-                {syncMsg}
-              </p>
-            )}
-          </>
-        ) : status?.configured ? (
-          <Button
-            variant="outline"
-            onClick={() => {
-              window.location.href = "/api/withings/connect";
-            }}
-          >
-            <Link2 className="h-4 w-4" />
-            {t("settings.withingsConnect")}
-          </Button>
-        ) : (
-          <div className="bg-muted/50 text-muted-foreground rounded-lg p-3 text-sm">
-            {t("settings.withingsNoCredentials")}
-          </div>
-        )}
-      </div>
-    </div>
-  );
-}
-
-function WhoopCard({
-  viewModel,
-}: {
-  viewModel: IntegrationStatusViewModel | undefined;
-}) {
-  const { t } = useTranslations();
-  const [syncing, setSyncing] = useState(false);
-  const [syncMsg, setSyncMsg] = useState<string | null>(null);
-  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
-    null,
-  );
-  const [clientId, setClientId] = useState("");
-  const [clientSecret, setClientSecret] = useState("");
-  const [credsSaving, setCredsSaving] = useState(false);
-  const [credsMsg, setCredsMsg] = useState<string | null>(null);
-  const [credsMsgType, setCredsMsgType] = useState<"success" | "error" | null>(
-    null,
-  );
-  const queryClient = useQueryClient();
-
-  // v1.12.1 — read off the consolidated /api/integrations/status
-  // envelope; the per-card /api/whoop/status round-trip is gone.
-  const status = viewModel;
-
-  const disconnect = useMutation({
-    mutationFn: async () => {
-      const res = await fetch("/api/whoop/disconnect", { method: "POST" });
-      if (!res.ok) throw new Error("Failed");
-    },
-    onSuccess: () => {
-      queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
-      queryClient.invalidateQueries({
-        queryKey: queryKeys.integrationsStatus(),
-      });
-    },
-  });
-
-  // Clear a parked integration via the resume endpoint. The CTA is
-  // rendered inside the parked banner below; success invalidates both
-  // the per-card status (so the pill flips back to connected
-  // immediately) and the cross-integration envelope (so any other view
-  // picks up the change on its next focus).
-  const resume = useMutation({
-    mutationFn: async () => {
-      const res = await fetch("/api/integrations/whoop/resume", {
-        method: "POST",
-      });
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as {
-        resumed: boolean;
-        wasParked: boolean;
-      };
-    },
-    onSuccess: () => {
-      queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
-      queryClient.invalidateQueries({
-        queryKey: queryKeys.integrationsStatus(),
-      });
-    },
-  });
-
-  async function handleSync(fullSync = false) {
-    setSyncing(true);
-    setSyncMsg(null);
-    setSyncMsgType(null);
-    try {
-      const res = await fetch("/api/whoop/sync", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ fullSync }),
-      });
-      const json = await res.json();
-      if (res.ok) {
-        setSyncMsg(
-          t("settings.whoopSyncResult", { count: json.data.imported }),
-        );
-        setSyncMsgType("success");
-        void invalidateKeys(queryClient, measurementDependentKeys);
-        queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
-        queryClient.invalidateQueries({
-          queryKey: queryKeys.integrationsStatus(),
-        });
-      } else {
-        setSyncMsg(json.error || t("settings.whoopSyncFailed"));
-        setSyncMsgType("error");
-      }
-    } catch {
-      setSyncMsg(t("settings.whoopSyncFailed"));
-      setSyncMsgType("error");
-    } finally {
-      setSyncing(false);
-    }
-  }
-
-  async function handleSaveCredentials(e: React.FormEvent) {
-    e.preventDefault();
-    setCredsSaving(true);
-    setCredsMsg(null);
-    setCredsMsgType(null);
-
-    try {
-      const res = await fetch("/api/whoop/credentials", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          clientId: clientId.trim(),
-          clientSecret: clientSecret.trim(),
-        }),
-      });
-
-      if (res.ok) {
-        setCredsMsg(t("settings.whoopCredentialsSaved"));
-        setCredsMsgType("success");
-        setClientId("");
-        setClientSecret("");
-        queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
-      } else {
-        try {
-          const json = await res.json();
-          setCredsMsg(json.error || t("settings.savingError"));
-        } catch {
-          setCredsMsg(t("settings.savingError"));
-        }
-        setCredsMsgType("error");
-      }
-    } catch {
-      setCredsMsg(t("common.networkError"));
-      setCredsMsgType("error");
-    }
-    setCredsSaving(false);
-  }
-
-  const pillState: IntegrationPillState = status?.connected
-    ? pillStateFor(viewModel)
-    : "disconnected";
-  const pillLastSyncAt =
-    status?.legacyLastSyncedAt ?? viewModel?.lastSuccessAt ?? null;
-  const errorMessage =
-    (pillState === "error" || pillState === "parked") && viewModel?.lastError
-      ? viewModel.lastError
-      : null;
-
-  return (
-    <div className="bg-card border-border rounded-xl border p-6">
-      <SettingsCardHeader
-        icon={Activity}
-        title={t("settings.whoop")}
-        description={
-          <>
-            <p>{t("settings.whoopDescription")}</p>
-            <p className="text-muted-foreground/80">
-              {t("settings.whoopOverlapNote")}
-            </p>
-          </>
-        }
-        status={
-          <IntegrationStatusPill
-            state={pillState}
-            lastSyncAt={pillLastSyncAt}
-          />
-        }
-      />
-
-      <hr
-        data-testid="integration-card-divider"
-        className="border-border/60 mt-4"
-      />
-
-      <div className="mt-4 space-y-4 pl-7">
-        {errorMessage && <IntegrationErrorMessage message={errorMessage} />}
-        {/* Parked-integration resume CTA. Surfaces only when the row
-            state is `parked` (>24h of persistent failures). The button
-            POSTs to /api/integrations/whoop/resume which calls
-            `resumeIntegrationFromPark`; on success the per-card status
-            invalidates and the pill flips back to connected without a
-            page refresh. Wider tap target than the inline action row so
-            it stays reachable on a Pixel 5 viewport. */}
-        {pillState === "parked" && (
-          <div
-            data-testid="whoop-parked-banner"
-            className="border-warning/30 bg-warning/10 flex flex-wrap items-center justify-between gap-2 rounded-md border px-3 py-2 text-sm"
-          >
-            <span className="text-warning min-w-0 text-xs break-words">
-              {t("settings.integrationPill.parkedReconnect")}
-            </span>
-            <Button
-              type="button"
-              size="sm"
-              variant="outline"
-              onClick={() => resume.mutate()}
-              disabled={resume.isPending}
-              data-testid="whoop-resume-button"
-              className="min-h-11"
-            >
-              {resume.isPending ? (
-                <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-              ) : (
-                <Link2 className="h-3.5 w-3.5" />
-              )}
-              {t("settings.integrationPill.resumeCta")}
-            </Button>
-          </div>
-        )}
-        {resume.isError && (
-          <p
-            role="alert"
-            className="text-destructive text-sm"
-            data-testid="whoop-resume-error"
-          >
-            {t("settings.integrationPill.resumeError")}
-          </p>
-        )}
-        {resume.isSuccess && resume.data?.wasParked && (
-          <p
-            role="status"
-            className="text-success text-xs"
-            data-testid="whoop-resume-success"
-          >
-            {t("settings.integrationPill.resumeSuccess")}
-          </p>
-        )}
-
-        <div className="space-y-3">
-          <h3 className="text-sm font-semibold">
-            {t("settings.whoopCredentials")}
-          </h3>
-          <p className="text-muted-foreground text-xs">
-            {t("settings.whoopCredentialsHelp")}
-          </p>
-          <form onSubmit={handleSaveCredentials} className="space-y-3">
-            <div className="grid gap-3 sm:grid-cols-2">
-              <div className="space-y-1.5">
-                <Label htmlFor="whoop-clientid">
-                  {t("settings.whoopClientId")}
-                </Label>
-                <Input
-                  id="whoop-clientid"
-                  value={clientId}
-                  onChange={(e) => setClientId(e.target.value)}
-                  placeholder={
-                    status?.configured
-                      ? t("settings.whoopCredentialsSavedPlaceholder")
-                      : t("settings.whoopClientId")
-                  }
-                  maxLength={200}
-                  autoComplete="off"
-                  inputMode="text"
-                  spellCheck={false}
-                  autoCapitalize="none"
-                  enterKeyHint="next"
-                />
-              </div>
-              <div className="space-y-1.5">
-                <Label htmlFor="whoop-secret">
-                  {t("settings.whoopClientSecret")}
-                </Label>
-                <PasswordInput
-                  id="whoop-secret"
-                  value={clientSecret}
-                  onChange={(e) => setClientSecret(e.target.value)}
-                  placeholder={
-                    status?.configured
-                      ? t("settings.whoopCredentialsSavedPlaceholderSecret")
-                      : t("settings.whoopClientSecret")
-                  }
-                  maxLength={200}
-                  autoComplete="off"
-                  inputMode="text"
-                  spellCheck={false}
-                  autoCapitalize="none"
-                  enterKeyHint="done"
-                />
-              </div>
-            </div>
-            <div className="flex justify-end">
-              <Button
-                type="submit"
-                variant="outline"
-                size="sm"
-                className="min-h-11 w-full sm:w-auto"
-                disabled={
-                  credsSaving || !clientId.trim() || !clientSecret.trim()
-                }
-              >
-                {credsSaving ? (
-                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                ) : (
-                  <Save className="h-3.5 w-3.5" />
-                )}
-                {t("settings.whoopSaveCredentials")}
-              </Button>
-            </div>
-            {credsMsg && (
-              <p
-                role="alert"
-                className={`text-sm ${credsMsgType === "success" ? "text-success" : "text-destructive"}`}
-              >
-                {credsMsg}
-              </p>
-            )}
-          </form>
-        </div>
-
-        {status?.connected ? (
-          <>
-            <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
-              <Button
-                variant="outline"
-                size="sm"
-                className="min-h-11"
-                onClick={() => handleSync(false)}
-                disabled={syncing}
-              >
-                {syncing ? (
-                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                ) : (
-                  <RefreshCw className="h-3.5 w-3.5" />
-                )}
-                {t("settings.whoopSync")}
-              </Button>
-              <AlertDialog>
-                <AlertDialogTrigger asChild>
-                  <Button
-                    variant="outline"
-                    size="sm"
-                    className="min-h-11"
-                    disabled={syncing}
-                  >
-                    {syncing ? (
-                      <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                    ) : (
-                      <RefreshCw className="h-3.5 w-3.5" />
-                    )}
-                    {t("settings.whoopFullSync")}
-                  </Button>
-                </AlertDialogTrigger>
-                <AlertDialogContent>
-                  <AlertDialogHeader>
-                    <AlertDialogTitle>
-                      {t("settings.whoopFullSyncTitle")}
-                    </AlertDialogTitle>
-                    <AlertDialogDescription>
-                      {t("settings.whoopFullSyncDescription")}
-                    </AlertDialogDescription>
-                  </AlertDialogHeader>
-                  <AlertDialogFooter>
-                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
-                    <AlertDialogAction onClick={() => handleSync(true)}>
-                      {t("settings.whoopSynchronize")}
-                    </AlertDialogAction>
-                  </AlertDialogFooter>
-                </AlertDialogContent>
-              </AlertDialog>
-              <TestConnectionButton
-                endpoint="/api/integrations/whoop/test"
-                disabled={!status?.connected}
-              />
-              <AlertDialog>
-                <AlertDialogTrigger asChild>
-                  <Button
-                    variant="outline"
-                    size="sm"
-                    className="text-destructive min-h-11"
-                  >
-                    <Unlink className="h-3.5 w-3.5" />
-                    {t("settings.whoopDisconnect")}
-                  </Button>
-                </AlertDialogTrigger>
-                <AlertDialogContent>
-                  <AlertDialogHeader>
-                    <AlertDialogTitle>
-                      {t("settings.whoopDisconnectTitle")}
-                    </AlertDialogTitle>
-                    <AlertDialogDescription>
-                      {t("settings.whoopDisconnectDescription")}
-                    </AlertDialogDescription>
-                  </AlertDialogHeader>
-                  <AlertDialogFooter>
-                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
-                    <AlertDialogAction
-                      variant="destructive"
-                      onClick={() => disconnect.mutate()}
-                    >
-                      {t("settings.whoopDisconnect")}
-                    </AlertDialogAction>
-                  </AlertDialogFooter>
-                </AlertDialogContent>
-              </AlertDialog>
-            </div>
-            {status?.backfillCompleted === false && (
-              <p className="text-muted-foreground text-xs">
-                {t("settings.whoopBackfillInProgress")}
-              </p>
-            )}
-            {syncMsg && (
-              <p
-                role="alert"
-                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
-              >
-                {syncMsg}
-              </p>
-            )}
-          </>
-        ) : status?.configured ? (
-          <Button
-            variant="outline"
-            onClick={() => {
-              window.location.href = "/api/whoop/connect";
-            }}
-          >
-            <Link2 className="h-4 w-4" />
-            {t("settings.whoopConnect")}
-          </Button>
-        ) : (
-          <div className="bg-muted/50 text-muted-foreground rounded-lg p-3 text-sm">
-            {t("settings.whoopNoCredentials")}
-          </div>
-        )}
-      </div>
-    </div>
-  );
-}
-
-// v1.12.0 — Google Health (Fitbit & Pixel) card. Mirrors the WHOOP card: a
-// BYO-key credentials form first, then an OAuth connect, then the
-// sync/test/disconnect action row + parked-resume banner. v1.12.1 — status
-// reads off the consolidated /api/integrations/status envelope (the per-card
-// /api/fitbit/status round-trip is gone); the pill/error/parked state comes off
-// the same view-model like WHOOP.
-function FitbitCard({
-  viewModel,
-}: {
-  viewModel: IntegrationStatusViewModel | undefined;
-}) {
-  const { t } = useTranslations();
-  const [syncing, setSyncing] = useState(false);
-  const [syncMsg, setSyncMsg] = useState<string | null>(null);
-  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
-    null,
-  );
-  const [clientId, setClientId] = useState("");
-  const [clientSecret, setClientSecret] = useState("");
-  const [credsSaving, setCredsSaving] = useState(false);
-  const [credsMsg, setCredsMsg] = useState<string | null>(null);
-  const [credsMsgType, setCredsMsgType] = useState<"success" | "error" | null>(
-    null,
-  );
-  const queryClient = useQueryClient();
-
-  const status = viewModel;
-
-  const disconnect = useMutation({
-    mutationFn: async () => {
-      const res = await fetch("/api/fitbit/disconnect", { method: "POST" });
-      if (!res.ok) throw new Error("Failed");
-    },
-    onSuccess: () => {
-      queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
-      queryClient.invalidateQueries({
-        queryKey: queryKeys.integrationsStatus(),
-      });
-    },
-  });
-
-  // Clear a parked integration via the resume endpoint. The CTA is
-  // rendered inside the parked banner below; success invalidates both
-  // the per-card status (so the pill flips back to connected
-  // immediately) and the cross-integration envelope (so any other view
-  // picks up the change on its next focus).
-  const resume = useMutation({
-    mutationFn: async () => {
-      const res = await fetch("/api/integrations/fitbit/resume", {
-        method: "POST",
-      });
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as {
-        resumed: boolean;
-        wasParked: boolean;
-      };
-    },
-    onSuccess: () => {
-      queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
-      queryClient.invalidateQueries({
-        queryKey: queryKeys.integrationsStatus(),
-      });
-    },
-  });
-
-  async function handleSync(fullSync = false) {
-    setSyncing(true);
-    setSyncMsg(null);
-    setSyncMsgType(null);
-    try {
-      const res = await fetch("/api/fitbit/sync", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ fullSync }),
-      });
-      const json = await res.json();
-      if (res.ok) {
-        setSyncMsg(
-          t("settings.fitbitSyncResult", { count: json.data.imported }),
-        );
-        setSyncMsgType("success");
-        void invalidateKeys(queryClient, measurementDependentKeys);
-        queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
-        queryClient.invalidateQueries({
-          queryKey: queryKeys.integrationsStatus(),
-        });
-      } else {
-        setSyncMsg(json.error || t("settings.fitbitSyncFailed"));
-        setSyncMsgType("error");
-      }
-    } catch {
-      setSyncMsg(t("settings.fitbitSyncFailed"));
-      setSyncMsgType("error");
-    } finally {
-      setSyncing(false);
-    }
-  }
-
-  async function handleSaveCredentials(e: React.FormEvent) {
-    e.preventDefault();
-    setCredsSaving(true);
-    setCredsMsg(null);
-    setCredsMsgType(null);
-
-    try {
-      const res = await fetch("/api/fitbit/credentials", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
-          clientId: clientId.trim(),
-          clientSecret: clientSecret.trim(),
-        }),
-      });
-
-      if (res.ok) {
-        setCredsMsg(t("settings.fitbitCredentialsSaved"));
-        setCredsMsgType("success");
-        setClientId("");
-        setClientSecret("");
-        queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
-      } else {
-        try {
-          const json = await res.json();
-          setCredsMsg(json.error || t("settings.savingError"));
-        } catch {
-          setCredsMsg(t("settings.savingError"));
-        }
-        setCredsMsgType("error");
-      }
-    } catch {
-      setCredsMsg(t("common.networkError"));
-      setCredsMsgType("error");
-    }
-    setCredsSaving(false);
-  }
-
-  const pillState: IntegrationPillState = status?.connected
-    ? pillStateFor(viewModel)
-    : "disconnected";
-  const pillLastSyncAt =
-    status?.legacyLastSyncedAt ?? viewModel?.lastSuccessAt ?? null;
-  const errorMessage =
-    (pillState === "error" || pillState === "parked") && viewModel?.lastError
-      ? viewModel.lastError
-      : null;
-
-  return (
-    <div
-      data-testid="fitbit-card"
-      className="bg-card border-border rounded-xl border p-6"
-    >
-      <SettingsCardHeader
-        icon={HeartPulse}
-        title={t("settings.fitbit")}
-        titleAccessory={
-          <>
-            <span className="bg-muted text-foreground rounded-full px-2 py-0.5 text-[0.6875rem] font-medium">
-              {t("settings.fitbitTag")}
-            </span>
-            <Badge
-              variant="outline"
-              data-testid="fitbit-experimental-badge"
-              className="border-amber-500/50 text-amber-600 dark:text-amber-400"
-            >
-              {t("settings.fitbitExperimentalBadge")}
-            </Badge>
-          </>
-        }
-        description={
-          <>
-            <p>{t("settings.fitbitDescription")}</p>
-            <p
-              data-testid="fitbit-experimental-note"
-              className="text-muted-foreground/80"
-            >
-              {t("settings.fitbitExperimentalNote")}
-            </p>
-            <p className="text-muted-foreground/80">
-              {t("settings.fitbitOverlapNote")}
-            </p>
-          </>
-        }
-        status={
-          <IntegrationStatusPill
-            state={pillState}
-            lastSyncAt={pillLastSyncAt}
-          />
-        }
-      />
-
-      <hr
-        data-testid="integration-card-divider"
-        className="border-border/60 mt-4"
-      />
-
-      <div className="mt-4 space-y-4 pl-7">
-        {errorMessage && <IntegrationErrorMessage message={errorMessage} />}
-        {/* Parked-integration resume CTA. Surfaces only when the row
-            state is `parked` (>24h of persistent failures). The button
-            POSTs to /api/integrations/fitbit/resume which calls
-            `resumeIntegrationFromPark`; on success the per-card status
-            invalidates and the pill flips back to connected without a
-            page refresh. */}
-        {pillState === "parked" && (
-          <div
-            data-testid="fitbit-parked-banner"
-            className="border-warning/30 bg-warning/10 flex flex-wrap items-center justify-between gap-2 rounded-md border px-3 py-2 text-sm"
-          >
-            <span className="text-warning min-w-0 text-xs break-words">
-              {t("settings.integrationPill.parkedReconnect")}
-            </span>
-            <Button
-              type="button"
-              size="sm"
-              variant="outline"
-              onClick={() => resume.mutate()}
-              disabled={resume.isPending}
-              data-testid="fitbit-resume-button"
-              className="min-h-11"
-            >
-              {resume.isPending ? (
-                <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-              ) : (
-                <Link2 className="h-3.5 w-3.5" />
-              )}
-              {t("settings.integrationPill.resumeCta")}
-            </Button>
-          </div>
-        )}
-        {resume.isError && (
-          <p
-            role="alert"
-            className="text-destructive text-sm"
-            data-testid="fitbit-resume-error"
-          >
-            {t("settings.integrationPill.resumeError")}
-          </p>
-        )}
-        {resume.isSuccess && resume.data?.wasParked && (
-          <p
-            role="status"
-            className="text-success text-xs"
-            data-testid="fitbit-resume-success"
-          >
-            {t("settings.integrationPill.resumeSuccess")}
-          </p>
-        )}
-
-        <div className="space-y-3">
-          <h3 className="text-sm font-semibold">
-            {t("settings.fitbitCredentials")}
-          </h3>
-          <p className="text-muted-foreground text-xs">
-            {t("settings.fitbitCredentialsHelp")}
-          </p>
-          <form onSubmit={handleSaveCredentials} className="space-y-3">
-            <div className="grid gap-3 sm:grid-cols-2">
-              <div className="space-y-1.5">
-                <Label htmlFor="fitbit-clientid">
-                  {t("settings.fitbitClientId")}
-                </Label>
-                <Input
-                  id="fitbit-clientid"
-                  value={clientId}
-                  onChange={(e) => setClientId(e.target.value)}
-                  placeholder={
-                    status?.configured
-                      ? t("settings.fitbitCredentialsSavedPlaceholder")
-                      : t("settings.fitbitClientId")
-                  }
-                  maxLength={200}
-                  autoComplete="off"
-                  inputMode="text"
-                  spellCheck={false}
-                  autoCapitalize="none"
-                  enterKeyHint="next"
-                />
-              </div>
-              <div className="space-y-1.5">
-                <Label htmlFor="fitbit-secret">
-                  {t("settings.fitbitClientSecret")}
-                </Label>
-                <PasswordInput
-                  id="fitbit-secret"
-                  value={clientSecret}
-                  onChange={(e) => setClientSecret(e.target.value)}
-                  placeholder={
-                    status?.configured
-                      ? t("settings.fitbitCredentialsSavedPlaceholderSecret")
-                      : t("settings.fitbitClientSecret")
-                  }
-                  maxLength={200}
-                  autoComplete="off"
-                  inputMode="text"
-                  spellCheck={false}
-                  autoCapitalize="none"
-                  enterKeyHint="done"
-                />
-              </div>
-            </div>
-            <div className="flex justify-end">
-              <Button
-                type="submit"
-                variant="outline"
-                size="sm"
-                className="min-h-11 w-full sm:w-auto"
-                disabled={
-                  credsSaving || !clientId.trim() || !clientSecret.trim()
-                }
-              >
-                {credsSaving ? (
-                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                ) : (
-                  <Save className="h-3.5 w-3.5" />
-                )}
-                {t("settings.fitbitSaveCredentials")}
-              </Button>
-            </div>
-            {credsMsg && (
-              <p
-                role="alert"
-                className={`text-sm ${credsMsgType === "success" ? "text-success" : "text-destructive"}`}
-              >
-                {credsMsg}
-              </p>
-            )}
-          </form>
-        </div>
-
-        {status?.connected ? (
-          <>
-            <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
-              <Button
-                variant="outline"
-                size="sm"
-                className="min-h-11"
-                onClick={() => handleSync(false)}
-                disabled={syncing}
-              >
-                {syncing ? (
-                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                ) : (
-                  <RefreshCw className="h-3.5 w-3.5" />
-                )}
-                {t("settings.fitbitSync")}
-              </Button>
-              <AlertDialog>
-                <AlertDialogTrigger asChild>
-                  <Button
-                    variant="outline"
-                    size="sm"
-                    className="min-h-11"
-                    disabled={syncing}
-                  >
-                    {syncing ? (
-                      <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
-                    ) : (
-                      <RefreshCw className="h-3.5 w-3.5" />
-                    )}
-                    {t("settings.fitbitFullSync")}
-                  </Button>
-                </AlertDialogTrigger>
-                <AlertDialogContent>
-                  <AlertDialogHeader>
-                    <AlertDialogTitle>
-                      {t("settings.fitbitFullSyncTitle")}
-                    </AlertDialogTitle>
-                    <AlertDialogDescription>
-                      {t("settings.fitbitFullSyncDescription")}
-                    </AlertDialogDescription>
-                  </AlertDialogHeader>
-                  <AlertDialogFooter>
-                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
-                    <AlertDialogAction onClick={() => handleSync(true)}>
-                      {t("settings.fitbitSynchronize")}
-                    </AlertDialogAction>
-                  </AlertDialogFooter>
-                </AlertDialogContent>
-              </AlertDialog>
-              <TestConnectionButton
-                endpoint="/api/integrations/fitbit/test"
-                disabled={!status?.connected}
-              />
-              <AlertDialog>
-                <AlertDialogTrigger asChild>
-                  <Button
-                    variant="outline"
-                    size="sm"
-                    className="text-destructive min-h-11"
-                  >
-                    <Unlink className="h-3.5 w-3.5" />
-                    {t("settings.fitbitDisconnect")}
-                  </Button>
-                </AlertDialogTrigger>
-                <AlertDialogContent>
-                  <AlertDialogHeader>
-                    <AlertDialogTitle>
-                      {t("settings.fitbitDisconnectTitle")}
-                    </AlertDialogTitle>
-                    <AlertDialogDescription>
-                      {t("settings.fitbitDisconnectDescription")}
-                    </AlertDialogDescription>
-                  </AlertDialogHeader>
-                  <AlertDialogFooter>
-                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
-                    <AlertDialogAction
-                      variant="destructive"
-                      onClick={() => disconnect.mutate()}
-                    >
-                      {t("settings.fitbitDisconnect")}
-                    </AlertDialogAction>
-                  </AlertDialogFooter>
-                </AlertDialogContent>
-              </AlertDialog>
-            </div>
-            {status?.backfillCompleted === false && (
-              <p className="text-muted-foreground text-xs">
-                {t("settings.fitbitBackfillInProgress")}
-              </p>
-            )}
-            {syncMsg && (
-              <p
-                role="alert"
-                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
-              >
-                {syncMsg}
-              </p>
-            )}
-          </>
-        ) : status?.configured ? (
-          <Button
-            variant="outline"
-            onClick={() => {
-              window.location.href = "/api/fitbit/connect";
-            }}
-          >
-            <Link2 className="h-4 w-4" />
-            {t("settings.fitbitConnect")}
-          </Button>
-        ) : (
-          <div className="bg-muted/50 text-muted-foreground rounded-lg p-3 text-sm">
-            {t("settings.fitbitNoCredentials")}
-          </div>
-        )}
-      </div>
-    </div>
-  );
-}
diff --git a/src/components/settings/integrations/fitbit-card.tsx b/src/components/settings/integrations/fitbit-card.tsx
new file mode 100644
index 000000000..22f1c95ca
--- /dev/null
+++ b/src/components/settings/integrations/fitbit-card.tsx
@@ -0,0 +1,483 @@
+"use client";
+
+// v1.12.0 — Google Health (Fitbit & Pixel) card. Mirrors the WHOOP card: a
+// BYO-key credentials form first, then an OAuth connect, then the
+// sync/test/disconnect action row + parked-resume banner. v1.12.1 — status
+// reads off the consolidated /api/integrations/status envelope (the per-card
+// /api/fitbit/status round-trip is gone); the pill/error/parked state comes off
+// the same view-model like WHOOP.
+
+import { useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { HeartPulse, Link2, Loader2, RefreshCw, Save, Unlink } from "lucide-react";
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from "@/components/ui/alert-dialog";
+import { Badge } from "@/components/ui/badge";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { PasswordInput } from "@/components/ui/password-input";
+import { SettingsCardHeader } from "@/components/settings/_card-header";
+import { IntegrationStatusPill } from "@/components/settings/integration-status-pill";
+import type { IntegrationPillState } from "@/components/settings/integration-status-pill";
+import { TestConnectionButton } from "@/components/settings/test-connection-button";
+import { apiFetchRaw, apiPost } from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
+import {
+  invalidateKeys,
+  measurementDependentKeys,
+  queryKeys,
+} from "@/lib/query-keys";
+
+import {
+  IntegrationErrorMessage,
+  pillStateFor,
+  type IntegrationStatusViewModel,
+} from "./shared";
+
+export function FitbitCard({
+  viewModel,
+}: {
+  viewModel: IntegrationStatusViewModel | undefined;
+}) {
+  const { t } = useTranslations();
+  const [syncing, setSyncing] = useState(false);
+  const [syncMsg, setSyncMsg] = useState<string | null>(null);
+  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
+  const [clientId, setClientId] = useState("");
+  const [clientSecret, setClientSecret] = useState("");
+  const [credsSaving, setCredsSaving] = useState(false);
+  const [credsMsg, setCredsMsg] = useState<string | null>(null);
+  const [credsMsgType, setCredsMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
+  const queryClient = useQueryClient();
+
+  const status = viewModel;
+
+  const disconnect = useMutation({
+    mutationFn: async () => {
+      await apiPost("/api/fitbit/disconnect");
+    },
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
+    },
+  });
+
+  // Clear a parked integration via the resume endpoint. The CTA is
+  // rendered inside the parked banner below; success invalidates both
+  // the per-card status (so the pill flips back to connected
+  // immediately) and the cross-integration envelope (so any other view
+  // picks up the change on its next focus).
+  const resume = useMutation({
+    mutationFn: async () => {
+      return apiPost<{ resumed: boolean; wasParked: boolean }>(
+        "/api/integrations/fitbit/resume",
+      );
+    },
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
+    },
+  });
+
+  async function handleSync(fullSync = false) {
+    setSyncing(true);
+    setSyncMsg(null);
+    setSyncMsgType(null);
+    try {
+      const res = await apiFetchRaw("/api/fitbit/sync", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ fullSync }),
+      });
+      const json = await res.json();
+      if (res.ok) {
+        setSyncMsg(
+          t("settings.fitbitSyncResult", { count: json.data.imported }),
+        );
+        setSyncMsgType("success");
+        void invalidateKeys(queryClient, measurementDependentKeys);
+        queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.integrationsStatus(),
+        });
+      } else {
+        setSyncMsg(json.error || t("settings.fitbitSyncFailed"));
+        setSyncMsgType("error");
+      }
+    } catch {
+      setSyncMsg(t("settings.fitbitSyncFailed"));
+      setSyncMsgType("error");
+    } finally {
+      setSyncing(false);
+    }
+  }
+
+  async function handleSaveCredentials(e: React.FormEvent) {
+    e.preventDefault();
+    setCredsSaving(true);
+    setCredsMsg(null);
+    setCredsMsgType(null);
+
+    try {
+      const res = await apiFetchRaw("/api/fitbit/credentials", {
+        method: "PUT",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          clientId: clientId.trim(),
+          clientSecret: clientSecret.trim(),
+        }),
+      });
+
+      if (res.ok) {
+        setCredsMsg(t("settings.fitbitCredentialsSaved"));
+        setCredsMsgType("success");
+        setClientId("");
+        setClientSecret("");
+        queryClient.invalidateQueries({ queryKey: queryKeys.fitbit() });
+      } else {
+        try {
+          const json = await res.json();
+          setCredsMsg(json.error || t("settings.savingError"));
+        } catch {
+          setCredsMsg(t("settings.savingError"));
+        }
+        setCredsMsgType("error");
+      }
+    } catch {
+      setCredsMsg(t("common.networkError"));
+      setCredsMsgType("error");
+    }
+    setCredsSaving(false);
+  }
+
+  const pillState: IntegrationPillState = status?.connected
+    ? pillStateFor(viewModel)
+    : "disconnected";
+  const pillLastSyncAt =
+    status?.legacyLastSyncedAt ?? viewModel?.lastSuccessAt ?? null;
+  const errorMessage =
+    (pillState === "error" || pillState === "parked") && viewModel?.lastError
+      ? viewModel.lastError
+      : null;
+
+  return (
+    <div
+      data-testid="fitbit-card"
+      className="bg-card border-border rounded-xl border p-6"
+    >
+      <SettingsCardHeader
+        icon={HeartPulse}
+        title={t("settings.fitbit")}
+        titleAccessory={
+          <>
+            <span className="bg-muted text-foreground rounded-full px-2 py-0.5 text-[0.6875rem] font-medium">
+              {t("settings.fitbitTag")}
+            </span>
+            <Badge
+              variant="outline"
+              data-testid="fitbit-experimental-badge"
+              className="border-amber-500/50 text-amber-600 dark:text-amber-400"
+            >
+              {t("settings.fitbitExperimentalBadge")}
+            </Badge>
+          </>
+        }
+        description={
+          <>
+            <p>{t("settings.fitbitDescription")}</p>
+            <p
+              data-testid="fitbit-experimental-note"
+              className="text-muted-foreground/80"
+            >
+              {t("settings.fitbitExperimentalNote")}
+            </p>
+            <p className="text-muted-foreground/80">
+              {t("settings.fitbitOverlapNote")}
+            </p>
+          </>
+        }
+        status={
+          <IntegrationStatusPill
+            state={pillState}
+            lastSyncAt={pillLastSyncAt}
+          />
+        }
+      />
+
+      <hr
+        data-testid="integration-card-divider"
+        className="border-border/60 mt-4"
+      />
+
+      <div className="mt-4 space-y-4 pl-7">
+        {errorMessage && <IntegrationErrorMessage message={errorMessage} />}
+        {/* Parked-integration resume CTA. Surfaces only when the row
+            state is `parked` (>24h of persistent failures). The button
+            POSTs to /api/integrations/fitbit/resume which calls
+            `resumeIntegrationFromPark`; on success the per-card status
+            invalidates and the pill flips back to connected without a
+            page refresh. */}
+        {pillState === "parked" && (
+          <div
+            data-testid="fitbit-parked-banner"
+            className="border-warning/30 bg-warning/10 flex flex-wrap items-center justify-between gap-2 rounded-md border px-3 py-2 text-sm"
+          >
+            <span className="text-warning min-w-0 text-xs break-words">
+              {t("settings.integrationPill.parkedReconnect")}
+            </span>
+            <Button
+              type="button"
+              size="sm"
+              variant="outline"
+              onClick={() => resume.mutate()}
+              disabled={resume.isPending}
+              data-testid="fitbit-resume-button"
+              className="min-h-11"
+            >
+              {resume.isPending ? (
+                <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+              ) : (
+                <Link2 className="h-3.5 w-3.5" />
+              )}
+              {t("settings.integrationPill.resumeCta")}
+            </Button>
+          </div>
+        )}
+        {resume.isError && (
+          <p
+            role="alert"
+            className="text-destructive text-sm"
+            data-testid="fitbit-resume-error"
+          >
+            {t("settings.integrationPill.resumeError")}
+          </p>
+        )}
+        {resume.isSuccess && resume.data?.wasParked && (
+          <p
+            role="status"
+            className="text-success text-xs"
+            data-testid="fitbit-resume-success"
+          >
+            {t("settings.integrationPill.resumeSuccess")}
+          </p>
+        )}
+
+        <div className="space-y-3">
+          <h3 className="text-sm font-semibold">
+            {t("settings.fitbitCredentials")}
+          </h3>
+          <p className="text-muted-foreground text-xs">
+            {t("settings.fitbitCredentialsHelp")}
+          </p>
+          <form onSubmit={handleSaveCredentials} className="space-y-3">
+            <div className="grid gap-3 sm:grid-cols-2">
+              <div className="space-y-1.5">
+                <Label htmlFor="fitbit-clientid">
+                  {t("settings.fitbitClientId")}
+                </Label>
+                <Input
+                  id="fitbit-clientid"
+                  value={clientId}
+                  onChange={(e) => setClientId(e.target.value)}
+                  placeholder={
+                    status?.configured
+                      ? t("settings.fitbitCredentialsSavedPlaceholder")
+                      : t("settings.fitbitClientId")
+                  }
+                  maxLength={200}
+                  autoComplete="off"
+                  inputMode="text"
+                  spellCheck={false}
+                  autoCapitalize="none"
+                  enterKeyHint="next"
+                />
+              </div>
+              <div className="space-y-1.5">
+                <Label htmlFor="fitbit-secret">
+                  {t("settings.fitbitClientSecret")}
+                </Label>
+                <PasswordInput
+                  id="fitbit-secret"
+                  value={clientSecret}
+                  onChange={(e) => setClientSecret(e.target.value)}
+                  placeholder={
+                    status?.configured
+                      ? t("settings.fitbitCredentialsSavedPlaceholderSecret")
+                      : t("settings.fitbitClientSecret")
+                  }
+                  maxLength={200}
+                  autoComplete="off"
+                  inputMode="text"
+                  spellCheck={false}
+                  autoCapitalize="none"
+                  enterKeyHint="done"
+                />
+              </div>
+            </div>
+            <div className="flex justify-end">
+              <Button
+                type="submit"
+                variant="outline"
+                size="sm"
+                className="min-h-11 w-full sm:w-auto"
+                disabled={
+                  credsSaving || !clientId.trim() || !clientSecret.trim()
+                }
+              >
+                {credsSaving ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <Save className="h-3.5 w-3.5" />
+                )}
+                {t("settings.fitbitSaveCredentials")}
+              </Button>
+            </div>
+            {credsMsg && (
+              <p
+                role="alert"
+                className={`text-sm ${credsMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {credsMsg}
+              </p>
+            )}
+          </form>
+        </div>
+
+        {status?.connected ? (
+          <>
+            <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
+              <Button
+                variant="outline"
+                size="sm"
+                className="min-h-11"
+                onClick={() => handleSync(false)}
+                disabled={syncing}
+              >
+                {syncing ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <RefreshCw className="h-3.5 w-3.5" />
+                )}
+                {t("settings.fitbitSync")}
+              </Button>
+              <AlertDialog>
+                <AlertDialogTrigger asChild>
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    className="min-h-11"
+                    disabled={syncing}
+                  >
+                    {syncing ? (
+                      <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                    ) : (
+                      <RefreshCw className="h-3.5 w-3.5" />
+                    )}
+                    {t("settings.fitbitFullSync")}
+                  </Button>
+                </AlertDialogTrigger>
+                <AlertDialogContent>
+                  <AlertDialogHeader>
+                    <AlertDialogTitle>
+                      {t("settings.fitbitFullSyncTitle")}
+                    </AlertDialogTitle>
+                    <AlertDialogDescription>
+                      {t("settings.fitbitFullSyncDescription")}
+                    </AlertDialogDescription>
+                  </AlertDialogHeader>
+                  <AlertDialogFooter>
+                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+                    <AlertDialogAction onClick={() => handleSync(true)}>
+                      {t("settings.fitbitSynchronize")}
+                    </AlertDialogAction>
+                  </AlertDialogFooter>
+                </AlertDialogContent>
+              </AlertDialog>
+              <TestConnectionButton
+                endpoint="/api/integrations/fitbit/test"
+                disabled={!status?.connected}
+              />
+              <AlertDialog>
+                <AlertDialogTrigger asChild>
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    className="text-destructive min-h-11"
+                  >
+                    <Unlink className="h-3.5 w-3.5" />
+                    {t("settings.fitbitDisconnect")}
+                  </Button>
+                </AlertDialogTrigger>
+                <AlertDialogContent>
+                  <AlertDialogHeader>
+                    <AlertDialogTitle>
+                      {t("settings.fitbitDisconnectTitle")}
+                    </AlertDialogTitle>
+                    <AlertDialogDescription>
+                      {t("settings.fitbitDisconnectDescription")}
+                    </AlertDialogDescription>
+                  </AlertDialogHeader>
+                  <AlertDialogFooter>
+                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+                    <AlertDialogAction
+                      variant="destructive"
+                      onClick={() => disconnect.mutate()}
+                    >
+                      {t("settings.fitbitDisconnect")}
+                    </AlertDialogAction>
+                  </AlertDialogFooter>
+                </AlertDialogContent>
+              </AlertDialog>
+            </div>
+            {status?.backfillCompleted === false && (
+              <p className="text-muted-foreground text-xs">
+                {t("settings.fitbitBackfillInProgress")}
+              </p>
+            )}
+            {syncMsg && (
+              <p
+                role="alert"
+                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {syncMsg}
+              </p>
+            )}
+          </>
+        ) : status?.configured ? (
+          <Button
+            variant="outline"
+            onClick={() => {
+              window.location.href = "/api/fitbit/connect";
+            }}
+          >
+            <Link2 className="h-4 w-4" />
+            {t("settings.fitbitConnect")}
+          </Button>
+        ) : (
+          <div className="bg-muted/50 text-muted-foreground rounded-lg p-3 text-sm">
+            {t("settings.fitbitNoCredentials")}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
diff --git a/src/components/settings/integrations/shared.tsx b/src/components/settings/integrations/shared.tsx
new file mode 100644
index 000000000..8990d6652
--- /dev/null
+++ b/src/components/settings/integrations/shared.tsx
@@ -0,0 +1,142 @@
+"use client";
+
+/**
+ * Shared types + status plumbing for the Settings → Integrations cards.
+ * Extracted from the former 1.6k-LOC `integrations-section.tsx`
+ * monolith; one card per integration lives next to this module under
+ * `src/components/settings/integrations/`.
+ */
+
+import { useQuery } from "@tanstack/react-query";
+import { AlertCircle } from "lucide-react";
+
+import type { IntegrationPillState } from "@/components/settings/integration-status-pill";
+import { apiGet } from "@/lib/api/api-fetch";
+import { queryKeys } from "@/lib/query-keys";
+
+// v1.4.15 Phase B2: shared status payload for both integration cards.
+// v1.4.19 Phase A5: the redundant in-card status banner is gone — the
+// IntegrationStatusPill now owns state + last-sync presentation, and
+// the actionable error message is shown inline above the action row.
+export type IntegrationKey = "withings" | "whoop" | "fitbit" | "moodlog";
+export type IntegrationState =
+  | "connected"
+  | "error_transient"
+  | "error_reauth"
+  | "disconnected"
+  | "parked";
+
+export interface IntegrationStatusViewModel {
+  integration: IntegrationKey;
+  state: IntegrationState;
+  lastSuccessAt: string | null;
+  lastAttemptAt: string | null;
+  lastError: string | null;
+  consecutiveFailuresByKind?: {
+    transient: number;
+    reauth_required: number;
+    persistent: number;
+  } | null;
+  configured?: boolean;
+  connected?: boolean;
+  connectedAt?: string | null;
+  legacyLastSyncedAt?: string | null;
+  tokenExpiresAt?: string | null;
+  tokenExpired?: boolean | null;
+  enabled?: boolean;
+  // Withings activity-scope reconnect banner.
+  scope?: string | null;
+  hasActivityScope?: boolean;
+  // WHOOP / Fitbit backfill-in-progress note.
+  backfillCompleted?: boolean | null;
+  // moodLog webhook secret + entry count.
+  webhookSecret?: string | null;
+  entryCount?: number;
+}
+
+export interface IntegrationStatusEnvelope {
+  threshold: number;
+  integrations: IntegrationStatusViewModel[];
+}
+
+/**
+ * Shared status fetch for the Settings → Integrations card. Returns
+ * the per-integration view-model AND the global threshold so the
+ * "{n}/{threshold} consecutive failures" string in the UI is single-
+ * sourced from the server.
+ */
+export function useIntegrationStatuses(enabled: boolean) {
+  return useQuery({
+    queryKey: queryKeys.integrationsStatus(),
+    queryFn: async () => {
+      return apiGet<IntegrationStatusEnvelope>("/api/integrations/status");
+    },
+    enabled,
+    refetchOnWindowFocus: true,
+  });
+}
+
+export function pickStatus(
+  envelope: IntegrationStatusEnvelope | undefined,
+  integration: IntegrationKey,
+): IntegrationStatusViewModel | undefined {
+  return envelope?.integrations.find((i) => i.integration === integration);
+}
+
+/**
+ * Collapse the API's five-state machine into the four states the
+ * pill UI cares about. `error_transient` and `error_reauth` both
+ * surface as the same "Error — reconnect" pill, the actionable
+ * difference (whether the user must reconnect vs wait for the next
+ * retry) is conveyed via the inline error text underneath. `parked`
+ * (v1.4.43 W14) is its own pill state — the integration has been
+ * disabled after 24h of persistent failures and needs an explicit
+ * "Wieder verbinden" click to resume.
+ */
+export function pillStateFor(
+  status: IntegrationStatusViewModel | undefined,
+): IntegrationPillState {
+  if (!status) return "disconnected";
+  switch (status.state) {
+    case "connected":
+      return "connected";
+    case "error_transient":
+      // v1.4.43 W4 H3 — a `persistent` failure-kind streak (Withings
+      // rate-limit 601 / contract-mismatch 293/294) maps to the same
+      // `error_transient` DB state as a normal retryable failure but
+      // tells the user a different story: the access token still
+      // works, the upstream is responding with a non-recoverable
+      // status. Surfacing it as a "warning" pill (orange) instead of
+      // the red "Fehler — neu verbinden" stops the user from clicking
+      // reconnect ten times when reconnect can't fix it.
+      if ((status.consecutiveFailuresByKind?.persistent ?? 0) > 0) {
+        return "warning";
+      }
+      return "error";
+    case "error_reauth":
+      return "error";
+    case "parked":
+      return "parked";
+    case "disconnected":
+      return "disconnected";
+  }
+}
+
+/**
+ * Inline actionable error message that surfaces under the pill when a
+ * sync attempt failed. The pill conveys "something is wrong"; this
+ * line tells the user *what* is wrong so they can act on it. Keeping
+ * it deliberately small (one icon + one line) so it doesn't recreate
+ * the v1.4.18 redundant banner the maintainer removed.
+ */
+export function IntegrationErrorMessage({ message }: { message: string }) {
+  return (
+    <p
+      data-testid="integration-error-message"
+      className="text-destructive flex items-start gap-1.5 text-sm"
+    >
+      <AlertCircle className="mt-0.5 h-3.5 w-3.5 shrink-0" />
+      <span className="min-w-0 break-words">{message}</span>
+    </p>
+  );
+}
diff --git a/src/components/settings/integrations/whoop-card.tsx b/src/components/settings/integrations/whoop-card.tsx
new file mode 100644
index 000000000..054461479
--- /dev/null
+++ b/src/components/settings/integrations/whoop-card.tsx
@@ -0,0 +1,455 @@
+"use client";
+
+import { useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { Activity, Link2, Loader2, RefreshCw, Save, Unlink } from "lucide-react";
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from "@/components/ui/alert-dialog";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { PasswordInput } from "@/components/ui/password-input";
+import { SettingsCardHeader } from "@/components/settings/_card-header";
+import { IntegrationStatusPill } from "@/components/settings/integration-status-pill";
+import type { IntegrationPillState } from "@/components/settings/integration-status-pill";
+import { TestConnectionButton } from "@/components/settings/test-connection-button";
+import { apiFetchRaw, apiPost } from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
+import {
+  invalidateKeys,
+  measurementDependentKeys,
+  queryKeys,
+} from "@/lib/query-keys";
+
+import {
+  IntegrationErrorMessage,
+  pillStateFor,
+  type IntegrationStatusViewModel,
+} from "./shared";
+
+export function WhoopCard({
+  viewModel,
+}: {
+  viewModel: IntegrationStatusViewModel | undefined;
+}) {
+  const { t } = useTranslations();
+  const [syncing, setSyncing] = useState(false);
+  const [syncMsg, setSyncMsg] = useState<string | null>(null);
+  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
+  const [clientId, setClientId] = useState("");
+  const [clientSecret, setClientSecret] = useState("");
+  const [credsSaving, setCredsSaving] = useState(false);
+  const [credsMsg, setCredsMsg] = useState<string | null>(null);
+  const [credsMsgType, setCredsMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
+  const queryClient = useQueryClient();
+
+  // v1.12.1 — read off the consolidated /api/integrations/status
+  // envelope; the per-card /api/whoop/status round-trip is gone.
+  const status = viewModel;
+
+  const disconnect = useMutation({
+    mutationFn: async () => {
+      await apiPost("/api/whoop/disconnect");
+    },
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
+    },
+  });
+
+  // Clear a parked integration via the resume endpoint. The CTA is
+  // rendered inside the parked banner below; success invalidates both
+  // the per-card status (so the pill flips back to connected
+  // immediately) and the cross-integration envelope (so any other view
+  // picks up the change on its next focus).
+  const resume = useMutation({
+    mutationFn: async () => {
+      return apiPost<{ resumed: boolean; wasParked: boolean }>(
+        "/api/integrations/whoop/resume",
+      );
+    },
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
+    },
+  });
+
+  async function handleSync(fullSync = false) {
+    setSyncing(true);
+    setSyncMsg(null);
+    setSyncMsgType(null);
+    try {
+      const res = await apiFetchRaw("/api/whoop/sync", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ fullSync }),
+      });
+      const json = await res.json();
+      if (res.ok) {
+        setSyncMsg(
+          t("settings.whoopSyncResult", { count: json.data.imported }),
+        );
+        setSyncMsgType("success");
+        void invalidateKeys(queryClient, measurementDependentKeys);
+        queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.integrationsStatus(),
+        });
+      } else {
+        setSyncMsg(json.error || t("settings.whoopSyncFailed"));
+        setSyncMsgType("error");
+      }
+    } catch {
+      setSyncMsg(t("settings.whoopSyncFailed"));
+      setSyncMsgType("error");
+    } finally {
+      setSyncing(false);
+    }
+  }
+
+  async function handleSaveCredentials(e: React.FormEvent) {
+    e.preventDefault();
+    setCredsSaving(true);
+    setCredsMsg(null);
+    setCredsMsgType(null);
+
+    try {
+      const res = await apiFetchRaw("/api/whoop/credentials", {
+        method: "PUT",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          clientId: clientId.trim(),
+          clientSecret: clientSecret.trim(),
+        }),
+      });
+
+      if (res.ok) {
+        setCredsMsg(t("settings.whoopCredentialsSaved"));
+        setCredsMsgType("success");
+        setClientId("");
+        setClientSecret("");
+        queryClient.invalidateQueries({ queryKey: queryKeys.whoop() });
+      } else {
+        try {
+          const json = await res.json();
+          setCredsMsg(json.error || t("settings.savingError"));
+        } catch {
+          setCredsMsg(t("settings.savingError"));
+        }
+        setCredsMsgType("error");
+      }
+    } catch {
+      setCredsMsg(t("common.networkError"));
+      setCredsMsgType("error");
+    }
+    setCredsSaving(false);
+  }
+
+  const pillState: IntegrationPillState = status?.connected
+    ? pillStateFor(viewModel)
+    : "disconnected";
+  const pillLastSyncAt =
+    status?.legacyLastSyncedAt ?? viewModel?.lastSuccessAt ?? null;
+  const errorMessage =
+    (pillState === "error" || pillState === "parked") && viewModel?.lastError
+      ? viewModel.lastError
+      : null;
+
+  return (
+    <div className="bg-card border-border rounded-xl border p-6">
+      <SettingsCardHeader
+        icon={Activity}
+        title={t("settings.whoop")}
+        description={
+          <>
+            <p>{t("settings.whoopDescription")}</p>
+            <p className="text-muted-foreground/80">
+              {t("settings.whoopOverlapNote")}
+            </p>
+          </>
+        }
+        status={
+          <IntegrationStatusPill
+            state={pillState}
+            lastSyncAt={pillLastSyncAt}
+          />
+        }
+      />
+
+      <hr
+        data-testid="integration-card-divider"
+        className="border-border/60 mt-4"
+      />
+
+      <div className="mt-4 space-y-4 pl-7">
+        {errorMessage && <IntegrationErrorMessage message={errorMessage} />}
+        {/* Parked-integration resume CTA. Surfaces only when the row
+            state is `parked` (>24h of persistent failures). The button
+            POSTs to /api/integrations/whoop/resume which calls
+            `resumeIntegrationFromPark`; on success the per-card status
+            invalidates and the pill flips back to connected without a
+            page refresh. Wider tap target than the inline action row so
+            it stays reachable on a Pixel 5 viewport. */}
+        {pillState === "parked" && (
+          <div
+            data-testid="whoop-parked-banner"
+            className="border-warning/30 bg-warning/10 flex flex-wrap items-center justify-between gap-2 rounded-md border px-3 py-2 text-sm"
+          >
+            <span className="text-warning min-w-0 text-xs break-words">
+              {t("settings.integrationPill.parkedReconnect")}
+            </span>
+            <Button
+              type="button"
+              size="sm"
+              variant="outline"
+              onClick={() => resume.mutate()}
+              disabled={resume.isPending}
+              data-testid="whoop-resume-button"
+              className="min-h-11"
+            >
+              {resume.isPending ? (
+                <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+              ) : (
+                <Link2 className="h-3.5 w-3.5" />
+              )}
+              {t("settings.integrationPill.resumeCta")}
+            </Button>
+          </div>
+        )}
+        {resume.isError && (
+          <p
+            role="alert"
+            className="text-destructive text-sm"
+            data-testid="whoop-resume-error"
+          >
+            {t("settings.integrationPill.resumeError")}
+          </p>
+        )}
+        {resume.isSuccess && resume.data?.wasParked && (
+          <p
+            role="status"
+            className="text-success text-xs"
+            data-testid="whoop-resume-success"
+          >
+            {t("settings.integrationPill.resumeSuccess")}
+          </p>
+        )}
+
+        <div className="space-y-3">
+          <h3 className="text-sm font-semibold">
+            {t("settings.whoopCredentials")}
+          </h3>
+          <p className="text-muted-foreground text-xs">
+            {t("settings.whoopCredentialsHelp")}
+          </p>
+          <form onSubmit={handleSaveCredentials} className="space-y-3">
+            <div className="grid gap-3 sm:grid-cols-2">
+              <div className="space-y-1.5">
+                <Label htmlFor="whoop-clientid">
+                  {t("settings.whoopClientId")}
+                </Label>
+                <Input
+                  id="whoop-clientid"
+                  value={clientId}
+                  onChange={(e) => setClientId(e.target.value)}
+                  placeholder={
+                    status?.configured
+                      ? t("settings.whoopCredentialsSavedPlaceholder")
+                      : t("settings.whoopClientId")
+                  }
+                  maxLength={200}
+                  autoComplete="off"
+                  inputMode="text"
+                  spellCheck={false}
+                  autoCapitalize="none"
+                  enterKeyHint="next"
+                />
+              </div>
+              <div className="space-y-1.5">
+                <Label htmlFor="whoop-secret">
+                  {t("settings.whoopClientSecret")}
+                </Label>
+                <PasswordInput
+                  id="whoop-secret"
+                  value={clientSecret}
+                  onChange={(e) => setClientSecret(e.target.value)}
+                  placeholder={
+                    status?.configured
+                      ? t("settings.whoopCredentialsSavedPlaceholderSecret")
+                      : t("settings.whoopClientSecret")
+                  }
+                  maxLength={200}
+                  autoComplete="off"
+                  inputMode="text"
+                  spellCheck={false}
+                  autoCapitalize="none"
+                  enterKeyHint="done"
+                />
+              </div>
+            </div>
+            <div className="flex justify-end">
+              <Button
+                type="submit"
+                variant="outline"
+                size="sm"
+                className="min-h-11 w-full sm:w-auto"
+                disabled={
+                  credsSaving || !clientId.trim() || !clientSecret.trim()
+                }
+              >
+                {credsSaving ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <Save className="h-3.5 w-3.5" />
+                )}
+                {t("settings.whoopSaveCredentials")}
+              </Button>
+            </div>
+            {credsMsg && (
+              <p
+                role="alert"
+                className={`text-sm ${credsMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {credsMsg}
+              </p>
+            )}
+          </form>
+        </div>
+
+        {status?.connected ? (
+          <>
+            <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
+              <Button
+                variant="outline"
+                size="sm"
+                className="min-h-11"
+                onClick={() => handleSync(false)}
+                disabled={syncing}
+              >
+                {syncing ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <RefreshCw className="h-3.5 w-3.5" />
+                )}
+                {t("settings.whoopSync")}
+              </Button>
+              <AlertDialog>
+                <AlertDialogTrigger asChild>
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    className="min-h-11"
+                    disabled={syncing}
+                  >
+                    {syncing ? (
+                      <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                    ) : (
+                      <RefreshCw className="h-3.5 w-3.5" />
+                    )}
+                    {t("settings.whoopFullSync")}
+                  </Button>
+                </AlertDialogTrigger>
+                <AlertDialogContent>
+                  <AlertDialogHeader>
+                    <AlertDialogTitle>
+                      {t("settings.whoopFullSyncTitle")}
+                    </AlertDialogTitle>
+                    <AlertDialogDescription>
+                      {t("settings.whoopFullSyncDescription")}
+                    </AlertDialogDescription>
+                  </AlertDialogHeader>
+                  <AlertDialogFooter>
+                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+                    <AlertDialogAction onClick={() => handleSync(true)}>
+                      {t("settings.whoopSynchronize")}
+                    </AlertDialogAction>
+                  </AlertDialogFooter>
+                </AlertDialogContent>
+              </AlertDialog>
+              <TestConnectionButton
+                endpoint="/api/integrations/whoop/test"
+                disabled={!status?.connected}
+              />
+              <AlertDialog>
+                <AlertDialogTrigger asChild>
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    className="text-destructive min-h-11"
+                  >
+                    <Unlink className="h-3.5 w-3.5" />
+                    {t("settings.whoopDisconnect")}
+                  </Button>
+                </AlertDialogTrigger>
+                <AlertDialogContent>
+                  <AlertDialogHeader>
+                    <AlertDialogTitle>
+                      {t("settings.whoopDisconnectTitle")}
+                    </AlertDialogTitle>
+                    <AlertDialogDescription>
+                      {t("settings.whoopDisconnectDescription")}
+                    </AlertDialogDescription>
+                  </AlertDialogHeader>
+                  <AlertDialogFooter>
+                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+                    <AlertDialogAction
+                      variant="destructive"
+                      onClick={() => disconnect.mutate()}
+                    >
+                      {t("settings.whoopDisconnect")}
+                    </AlertDialogAction>
+                  </AlertDialogFooter>
+                </AlertDialogContent>
+              </AlertDialog>
+            </div>
+            {status?.backfillCompleted === false && (
+              <p className="text-muted-foreground text-xs">
+                {t("settings.whoopBackfillInProgress")}
+              </p>
+            )}
+            {syncMsg && (
+              <p
+                role="alert"
+                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {syncMsg}
+              </p>
+            )}
+          </>
+        ) : status?.configured ? (
+          <Button
+            variant="outline"
+            onClick={() => {
+              window.location.href = "/api/whoop/connect";
+            }}
+          >
+            <Link2 className="h-4 w-4" />
+            {t("settings.whoopConnect")}
+          </Button>
+        ) : (
+          <div className="bg-muted/50 text-muted-foreground rounded-lg p-3 text-sm">
+            {t("settings.whoopNoCredentials")}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
diff --git a/src/components/settings/integrations/withings-card.tsx b/src/components/settings/integrations/withings-card.tsx
new file mode 100644
index 000000000..7722c1a97
--- /dev/null
+++ b/src/components/settings/integrations/withings-card.tsx
@@ -0,0 +1,497 @@
+"use client";
+
+import { useState } from "react";
+import { useMutation, useQueryClient } from "@tanstack/react-query";
+import { Link2, Loader2, RefreshCw, Save, Unlink } from "lucide-react";
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from "@/components/ui/alert-dialog";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Label } from "@/components/ui/label";
+import { PasswordInput } from "@/components/ui/password-input";
+import { SettingsCardHeader } from "@/components/settings/_card-header";
+import { IntegrationStatusPill } from "@/components/settings/integration-status-pill";
+import type { IntegrationPillState } from "@/components/settings/integration-status-pill";
+import { TestConnectionButton } from "@/components/settings/test-connection-button";
+import { apiFetchRaw, apiPost } from "@/lib/api/api-fetch";
+import { useTranslations } from "@/lib/i18n/context";
+import {
+  invalidateKeys,
+  measurementDependentKeys,
+  queryKeys,
+} from "@/lib/query-keys";
+
+import {
+  IntegrationErrorMessage,
+  pillStateFor,
+  type IntegrationStatusViewModel,
+} from "./shared";
+
+export function WithingsCard({
+  viewModel,
+}: {
+  viewModel: IntegrationStatusViewModel | undefined;
+}) {
+  const { t } = useTranslations();
+  const [syncing, setSyncing] = useState(false);
+  const [syncMsg, setSyncMsg] = useState<string | null>(null);
+  const [syncMsgType, setSyncMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
+  const [clientId, setClientId] = useState("");
+  const [clientSecret, setClientSecret] = useState("");
+  const [credsSaving, setCredsSaving] = useState(false);
+  const [credsMsg, setCredsMsg] = useState<string | null>(null);
+  const [credsMsgType, setCredsMsgType] = useState<"success" | "error" | null>(
+    null,
+  );
+  const queryClient = useQueryClient();
+
+  // v1.12.1 — the Withings status is read off the consolidated
+  // /api/integrations/status envelope (the `viewModel` prop). The
+  // per-card /api/withings/status round-trip is gone; the envelope
+  // carries every field this card renders (connected / configured /
+  // last-sync / activity scope).
+  const status = viewModel;
+
+  const disconnect = useMutation({
+    mutationFn: async () => {
+      await apiPost("/api/withings/disconnect");
+    },
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: queryKeys.withings() });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
+    },
+  });
+
+  // v1.4.43 W14 — clear a parked integration via the resume endpoint.
+  // The CTA is rendered inside the parked banner below; success
+  // invalidates both the per-card status (so the pill flips back to
+  // connected immediately) and the cross-integration envelope (so any
+  // other view picks up the change on its next focus).
+  const resume = useMutation({
+    mutationFn: async () => {
+      return apiPost<{ resumed: boolean; wasParked: boolean }>(
+        "/api/integrations/withings/resume",
+      );
+    },
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: queryKeys.withings() });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
+    },
+  });
+
+  async function handleSync(fullSync = false) {
+    setSyncing(true);
+    setSyncMsg(null);
+    setSyncMsgType(null);
+    try {
+      const res = await apiFetchRaw("/api/withings/sync", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ fullSync }),
+      });
+      const json = await res.json();
+      if (res.ok) {
+        setSyncMsg(
+          fullSync
+            ? t("settings.withingsFullSyncResult", {
+                count: json.data.imported,
+              })
+            : t("settings.withingsSyncResult", { count: json.data.imported }),
+        );
+        setSyncMsgType("success");
+        void invalidateKeys(queryClient, measurementDependentKeys);
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.integrationsStatus(),
+        });
+      } else {
+        setSyncMsg(json.error || t("settings.withingsSyncFailed"));
+        setSyncMsgType("error");
+      }
+    } catch {
+      setSyncMsg(t("settings.withingsSyncFailed"));
+      setSyncMsgType("error");
+    } finally {
+      setSyncing(false);
+    }
+  }
+
+  async function handleSaveCredentials(e: React.FormEvent) {
+    e.preventDefault();
+    setCredsSaving(true);
+    setCredsMsg(null);
+    setCredsMsgType(null);
+
+    try {
+      const res = await apiFetchRaw("/api/withings/credentials", {
+        method: "PUT",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          clientId: clientId.trim(),
+          clientSecret: clientSecret.trim(),
+        }),
+      });
+
+      if (res.ok) {
+        setCredsMsg(t("settings.withingsCredentialsSaved"));
+        setCredsMsgType("success");
+        setClientId("");
+        setClientSecret("");
+        queryClient.invalidateQueries({ queryKey: queryKeys.withings() });
+      } else {
+        try {
+          const json = await res.json();
+          setCredsMsg(json.error || t("settings.savingError"));
+        } catch {
+          setCredsMsg(t("settings.savingError"));
+        }
+        setCredsMsgType("error");
+      }
+    } catch {
+      setCredsMsg(t("common.networkError"));
+      setCredsMsgType("error");
+    }
+    setCredsSaving(false);
+  }
+
+  // The pill state derives from the cross-integration status
+  // envelope. `legacyLastSyncedAt` is the connection row's own
+  // last-sync timestamp (carried in the same envelope) so the pill
+  // still paints a fresh "X min ago" right after a manual sync once
+  // the envelope refetches. When the envelope hasn't answered yet we
+  // fall back to "disconnected" so the card never renders status-less.
+  const pillState: IntegrationPillState = status?.connected
+    ? pillStateFor(viewModel)
+    : "disconnected";
+  const pillLastSyncAt =
+    status?.legacyLastSyncedAt ?? viewModel?.lastSuccessAt ?? null;
+  // v1.4.43 W14 — `parked` and `error` both want the underlying error
+  // message surfaced under the pill (the pill says "what" — the
+  // message says "why"). Other states leave the inline line off.
+  const errorMessage =
+    (pillState === "error" || pillState === "parked") && viewModel?.lastError
+      ? viewModel.lastError
+      : null;
+
+  return (
+    <div className="bg-card border-border rounded-xl border p-6">
+      <SettingsCardHeader
+        icon={Link2}
+        title={t("settings.withings")}
+        description={t("settings.withingsDescription")}
+        status={
+          <IntegrationStatusPill
+            state={pillState}
+            lastSyncAt={pillLastSyncAt}
+          />
+        }
+      />
+
+      <hr
+        data-testid="integration-card-divider"
+        className="border-border/60 mt-4"
+      />
+
+      <div className="mt-4 space-y-4 pl-7">
+        {errorMessage && <IntegrationErrorMessage message={errorMessage} />}
+        {/* v1.4.25 W5d — Withings activity-scope reconnect banner.
+            Only paints when (a) the user has an active Withings
+            connection (so the credentials are already saved + a token
+            exists) AND (b) the persisted scope is missing
+            `user.activity`. Reconnecting takes the user through the
+            standard /api/withings/connect → Withings → callback flow;
+            the callback persists the upgraded scope and the banner
+            vanishes on the next status poll. */}
+        {status?.connected && status?.hasActivityScope === false && (
+          <a
+            href="/api/withings/connect"
+            data-testid="withings-reconnect-banner"
+            className="border-warning/30 bg-warning/10 text-warning-foreground hover:bg-warning/20 block rounded-md border px-3 py-2 text-sm transition-colors"
+          >
+            <span className="font-medium">
+              {t("settings.integrations.withings.reconnect.banner.title")}
+            </span>
+            <span className="text-muted-foreground block text-xs">
+              {t("settings.integrations.withings.reconnect.banner.body")}
+            </span>
+            <span className="text-primary mt-1 inline-block text-xs font-medium">
+              {t("settings.integrations.withings.reconnect.banner.action")}
+              {" →"}
+            </span>
+          </a>
+        )}
+        {/* v1.4.43 W14 — parked-integration resume CTA. Surfaces only
+            when the row state is `parked` (>24h of persistent
+            failures). The button POSTs to /api/integrations/withings/
+            resume which calls `resumeIntegrationFromPark`; on success
+            the per-card status invalidates and the pill flips back to
+            connected without a page refresh. The button is the
+            primary action the user can take from this card — wider
+            tap target than the inline action row so it's reachable
+            on a Pixel 5 viewport. */}
+        {pillState === "parked" && (
+          <div
+            data-testid="withings-parked-banner"
+            className="border-warning/30 bg-warning/10 flex flex-wrap items-center justify-between gap-2 rounded-md border px-3 py-2 text-sm"
+          >
+            <span className="text-warning min-w-0 text-xs break-words">
+              {t("settings.integrationPill.parkedReconnect")}
+            </span>
+            <Button
+              type="button"
+              size="sm"
+              variant="outline"
+              onClick={() => resume.mutate()}
+              disabled={resume.isPending}
+              data-testid="withings-resume-button"
+              className="min-h-11"
+            >
+              {resume.isPending ? (
+                <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+              ) : (
+                <Link2 className="h-3.5 w-3.5" />
+              )}
+              {t("settings.integrationPill.resumeCta")}
+            </Button>
+          </div>
+        )}
+        {resume.isError && (
+          <p
+            role="alert"
+            className="text-destructive text-sm"
+            data-testid="withings-resume-error"
+          >
+            {t("settings.integrationPill.resumeError")}
+          </p>
+        )}
+        {resume.isSuccess && resume.data?.wasParked && (
+          <p
+            role="status"
+            className="text-success text-xs"
+            data-testid="withings-resume-success"
+          >
+            {t("settings.integrationPill.resumeSuccess")}
+          </p>
+        )}
+        <div className="space-y-3">
+          <h3 className="text-sm font-semibold">
+            {t("settings.withingsCredentials")}
+          </h3>
+          <form onSubmit={handleSaveCredentials} className="space-y-3">
+            {/* v1.4.27 MB7 / CF-53 — the credentials grid drops from
+                a 3-column row (client-id / secret / save) to a
+                2-column row of inputs at `sm:`, with the Save button
+                lifted out into its own row below. The previous
+                "invisible Label" hack to align the button with the
+                input baselines fell apart on Galaxy Fold; lifting
+                the button into a dedicated `flex justify-end` row
+                gives it consistent placement on every viewport and
+                lets the input pair span the full width. */}
+            <div className="grid gap-3 sm:grid-cols-2">
+              <div className="space-y-1.5">
+                <Label htmlFor="w-clientid">
+                  {t("settings.withingsClientId")}
+                </Label>
+                <Input
+                  id="w-clientid"
+                  value={clientId}
+                  onChange={(e) => setClientId(e.target.value)}
+                  placeholder={
+                    status?.configured
+                      ? t("settings.withingsCredentialsSavedPlaceholder")
+                      : t("settings.withingsClientId")
+                  }
+                  maxLength={200}
+                  autoComplete="off"
+                  inputMode="text"
+                  spellCheck={false}
+                  autoCapitalize="none"
+                  enterKeyHint="next"
+                />
+              </div>
+              <div className="space-y-1.5">
+                <Label htmlFor="w-secret">
+                  {t("settings.withingsClientSecret")}
+                </Label>
+                <PasswordInput
+                  id="w-secret"
+                  value={clientSecret}
+                  onChange={(e) => setClientSecret(e.target.value)}
+                  placeholder={
+                    status?.configured
+                      ? t("settings.withingsCredentialsSavedPlaceholderSecret")
+                      : t("settings.withingsClientSecret")
+                  }
+                  maxLength={200}
+                  autoComplete="off"
+                  inputMode="text"
+                  spellCheck={false}
+                  autoCapitalize="none"
+                  enterKeyHint="done"
+                />
+              </div>
+            </div>
+            <div className="flex justify-end">
+              <Button
+                type="submit"
+                variant="outline"
+                size="sm"
+                className="min-h-11 w-full sm:w-auto"
+                disabled={
+                  credsSaving || !clientId.trim() || !clientSecret.trim()
+                }
+              >
+                {credsSaving ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <Save className="h-3.5 w-3.5" />
+                )}
+                {t("settings.withingsSaveCredentials")}
+              </Button>
+            </div>
+            {credsMsg && (
+              <p
+                role="alert"
+                className={`text-sm ${credsMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {credsMsg}
+              </p>
+            )}
+          </form>
+        </div>
+
+        {status?.connected ? (
+          <>
+            {/* v1.4.27 MB7 / CF-57 — the action row already wraps via
+                `flex-wrap`, but on Pixel 5 the four AlertDialog +
+                test-connection triggers each took a fractional slot
+                that read jagged. Force each button to a `min-w-[10rem]`
+                on `<sm` so they stack two per row at most and fill
+                their column cleanly. Tablet+ keeps the inline row. */}
+            <div className="flex flex-wrap items-start gap-2 [&>*]:min-w-[10rem] sm:[&>*]:min-w-0">
+              <Button
+                variant="outline"
+                size="sm"
+                className="min-h-11"
+                onClick={() => handleSync(false)}
+                disabled={syncing}
+              >
+                {syncing ? (
+                  <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                ) : (
+                  <RefreshCw className="h-3.5 w-3.5" />
+                )}
+                {t("settings.withingsSync")}
+              </Button>
+              <AlertDialog>
+                <AlertDialogTrigger asChild>
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    className="min-h-11"
+                    disabled={syncing}
+                  >
+                    {syncing ? (
+                      <Loader2 className="h-3.5 w-3.5 animate-spin motion-reduce:animate-none" />
+                    ) : (
+                      <RefreshCw className="h-3.5 w-3.5" />
+                    )}
+                    {t("settings.withingsFullSync")}
+                  </Button>
+                </AlertDialogTrigger>
+                <AlertDialogContent>
+                  <AlertDialogHeader>
+                    <AlertDialogTitle>
+                      {t("settings.withingsFullSyncTitle")}
+                    </AlertDialogTitle>
+                    <AlertDialogDescription>
+                      {t("settings.withingsFullSyncDescription")}
+                    </AlertDialogDescription>
+                  </AlertDialogHeader>
+                  <AlertDialogFooter>
+                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+                    <AlertDialogAction onClick={() => handleSync(true)}>
+                      {t("settings.withingsSynchronize")}
+                    </AlertDialogAction>
+                  </AlertDialogFooter>
+                </AlertDialogContent>
+              </AlertDialog>
+              <TestConnectionButton
+                endpoint="/api/integrations/withings/test"
+                disabled={!status?.connected}
+              />
+              <AlertDialog>
+                <AlertDialogTrigger asChild>
+                  <Button
+                    variant="outline"
+                    size="sm"
+                    className="text-destructive min-h-11"
+                  >
+                    <Unlink className="h-3.5 w-3.5" />
+                    {t("settings.withingsDisconnect")}
+                  </Button>
+                </AlertDialogTrigger>
+                <AlertDialogContent>
+                  <AlertDialogHeader>
+                    <AlertDialogTitle>
+                      {t("settings.withingsDisconnectTitle")}
+                    </AlertDialogTitle>
+                    <AlertDialogDescription>
+                      {t("settings.withingsDisconnectDescription")}
+                    </AlertDialogDescription>
+                  </AlertDialogHeader>
+                  <AlertDialogFooter>
+                    <AlertDialogCancel>{t("common.cancel")}</AlertDialogCancel>
+                    <AlertDialogAction
+                      variant="destructive"
+                      onClick={() => disconnect.mutate()}
+                    >
+                      {t("settings.withingsDisconnect")}
+                    </AlertDialogAction>
+                  </AlertDialogFooter>
+                </AlertDialogContent>
+              </AlertDialog>
+            </div>
+            {syncMsg && (
+              <p
+                role="alert"
+                className={`text-sm ${syncMsgType === "success" ? "text-success" : "text-destructive"}`}
+              >
+                {syncMsg}
+              </p>
+            )}
+          </>
+        ) : status?.configured ? (
+          <Button
+            variant="outline"
+            onClick={() => {
+              window.location.href = "/api/withings/connect";
+            }}
+          >
+            <Link2 className="h-4 w-4" />
+            {t("settings.withingsConnect")}
+          </Button>
+        ) : (
+          <div className="bg-muted/50 text-muted-foreground rounded-lg p-3 text-sm">
+            {t("settings.withingsNoCredentials")}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}
diff --git a/src/components/settings/mood-reminder-card.tsx b/src/components/settings/mood-reminder-card.tsx
index 9c7396bff..8d4d0fa0c 100644
--- a/src/components/settings/mood-reminder-card.tsx
+++ b/src/components/settings/mood-reminder-card.tsx
@@ -9,6 +9,7 @@ import { Switch } from "@/components/ui/switch";
 import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface ProfileShape {
   moodReminderEnabled: boolean;
@@ -65,9 +66,7 @@ export function MoodReminderCard({
   const { data: profile } = useQuery({
     queryKey: queryKeys.userProfile(),
     queryFn: async () => {
-      const res = await fetch("/api/user/profile");
-      if (!res.ok) throw new Error("Failed to load profile");
-      return (await res.json()).data as ProfileShape;
+      return apiGet<ProfileShape>("/api/user/profile");
     },
     enabled: isAuthenticated,
   });
@@ -77,9 +76,7 @@ export function MoodReminderCard({
   const { data: prefs } = useQuery({
     queryKey: queryKeys.authNotificationPrefs(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/me/notification-prefs");
-      if (!res.ok) throw new Error("Failed to load notification prefs");
-      return (await res.json()).data as NotificationPrefsShape;
+      return apiGet<NotificationPrefsShape>("/api/auth/me/notification-prefs");
     },
     enabled: isAuthenticated,
   });
@@ -97,7 +94,7 @@ export function MoodReminderCard({
       clearTimerRef.current = null;
     }
 
-    const res = await fetch("/api/user/profile", {
+    const res = await apiFetchRaw("/api/user/profile", {
       method: "PATCH",
       headers: { "Content-Type": "application/json" },
       body: JSON.stringify({ moodReminderEnabled: next }),
@@ -132,7 +129,7 @@ export function MoodReminderCard({
       clearTimerRef.current = null;
     }
 
-    const res = await fetch("/api/auth/me/notification-prefs", {
+    const res = await apiFetchRaw("/api/auth/me/notification-prefs", {
       method: "PATCH",
       headers: { "Content-Type": "application/json" },
       body: JSON.stringify({ mood: { reminderHour: next } }),
diff --git a/src/components/settings/notification-status-card.tsx b/src/components/settings/notification-status-card.tsx
index 9b1c10fa4..1791f7036 100644
--- a/src/components/settings/notification-status-card.tsx
+++ b/src/components/settings/notification-status-card.tsx
@@ -34,6 +34,7 @@ import { Button } from "@/components/ui/button";
 import { useAuth } from "@/hooks/use-auth";
 import { useFormatters, useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiGet, apiPost } from "@/lib/api/api-fetch";
 
 type ChannelType = "TELEGRAM" | "NTFY" | "WEB_PUSH" | "APNS";
 
@@ -73,10 +74,10 @@ export function NotificationStatusCard() {
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.notificationsStatus(),
     queryFn: async () => {
-      const res = await fetch("/api/notifications/status");
-      if (!res.ok) throw new Error("Failed");
-      return ((await res.json()).data as { channels: ChannelStatus[] })
-        .channels;
+      const data = await apiGet<{ channels: ChannelStatus[] }>(
+        "/api/notifications/status",
+      );
+      return data.channels;
     },
     enabled: isAuthenticated,
     refetchInterval: 30_000,
@@ -84,12 +85,7 @@ export function NotificationStatusCard() {
 
   const reEnable = useMutation({
     mutationFn: async (channelId: string) => {
-      const res = await fetch("/api/notifications/status", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ channelId }),
-      });
-      if (!res.ok) throw new Error("Failed");
+      await apiPost("/api/notifications/status", { channelId });
     },
     onSuccess: () => {
       queryClient.invalidateQueries({
diff --git a/src/components/settings/notifications-section.tsx b/src/components/settings/notifications-section.tsx
index f4bf8b6a5..ff95eb74f 100644
--- a/src/components/settings/notifications-section.tsx
+++ b/src/components/settings/notifications-section.tsx
@@ -13,6 +13,7 @@ import { NotificationStatusCard } from "@/components/settings/notification-statu
 import { NtfyCard } from "@/components/settings/ntfy-card";
 import { TelegramCard } from "@/components/settings/telegram-card";
 import { WebPushCard } from "@/components/settings/web-push-card";
+import { apiGet } from "@/lib/api/api-fetch";
 
 interface GlobalServiceAvailability {
   telegramGlobal: boolean;
@@ -29,9 +30,7 @@ export function NotificationsSection() {
   const { data: globalServices } = useQuery({
     queryKey: queryKeys.settingsGlobalServices(),
     queryFn: async () => {
-      const res = await fetch("/api/settings/global-services");
-      if (!res.ok) throw new Error("Failed");
-      return (await res.json()).data as GlobalServiceAvailability;
+      return apiGet<GlobalServiceAvailability>("/api/settings/global-services");
     },
     enabled: isAuthenticated,
   });
diff --git a/src/components/settings/ntfy-card.tsx b/src/components/settings/ntfy-card.tsx
index 8d6319dc6..7453a0fe5 100644
--- a/src/components/settings/ntfy-card.tsx
+++ b/src/components/settings/ntfy-card.tsx
@@ -13,6 +13,7 @@ import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { TestConnectionButton } from "@/components/settings/test-connection-button";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface NtfySettings {
   enabled: boolean;
@@ -35,10 +36,7 @@ export function NtfyCard({ isAuthenticated }: { isAuthenticated: boolean }) {
   const { data: settings } = useQuery({
     queryKey: queryKeys.settingsNtfy(),
     queryFn: async () => {
-      const res = await fetch("/api/settings/ntfy");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as NtfySettings;
+      return apiGet<NtfySettings>("/api/settings/ntfy");
     },
     enabled: isAuthenticated,
   });
@@ -56,7 +54,7 @@ export function NtfyCard({ isAuthenticated }: { isAuthenticated: boolean }) {
 
   const save = useMutation({
     mutationFn: async (enabled: boolean) => {
-      const res = await fetch("/api/settings/ntfy", {
+      const res = await apiFetchRaw("/api/settings/ntfy", {
         method: "PUT",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
diff --git a/src/components/settings/sources-section.tsx b/src/components/settings/sources-section.tsx
index 2799e30c5..2598d6b36 100644
--- a/src/components/settings/sources-section.tsx
+++ b/src/components/settings/sources-section.tsx
@@ -17,7 +17,7 @@
  * straight into iOS-era analytics without an extra migration step.
  *
  * v1.4.25 W8c — two-axis extension. The same screen now hosts three
- * vertically-stacked sections (Marc no-split directive):
+ * vertically-stacked sections (the maintainer no-split directive):
  *   1. Global default ladder per metric class (existing).
  *   2. Per-metric override expander — collapsed by default; an
  *      explicit knob for power users (the global ladder already lives
@@ -53,6 +53,7 @@ import {
   SOURCE_PRIORITY_METRIC_KEYS,
   type SourcePriorityMetricKey,
 } from "@/lib/validations/source-priority";
+import { apiGet, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * Resolved shape returned by `GET /api/auth/me/source-priority`. Mirrors
@@ -125,10 +126,7 @@ export function SourcesSection() {
   const { data: remote, isLoading } = useQuery({
     queryKey: queryKeys.sourcePriority(),
     queryFn: async () => {
-      const res = await fetch("/api/auth/me/source-priority");
-      if (!res.ok) throw new Error("failed");
-      const json = await res.json();
-      return json.data as ResolvedPriority;
+      return apiGet<ResolvedPriority>("/api/auth/me/source-priority");
     },
   });
 
@@ -151,13 +149,7 @@ export function SourcesSection() {
         metricPriority: next.metricPriority,
         deviceTypePriority: next.deviceTypePriority,
       };
-      const res = await fetch("/api/auth/me/source-priority", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
-      });
-      if (!res.ok) throw new Error("save failed");
-      return (await res.json()).data as ResolvedPriority;
+      return apiPut<ResolvedPriority>("/api/auth/me/source-priority", body);
     },
     onSuccess: (saved) => {
       queryClient.setQueryData(queryKeys.sourcePriority(), saved);
@@ -176,13 +168,7 @@ export function SourcesSection() {
       // Sending the empty W8c shape clears every per-user override; the
       // server's `parseSourcePriority` then returns the constant
       // defaults verbatim. Keeps the wire payload tiny.
-      const res = await fetch("/api/auth/me/source-priority", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({}),
-      });
-      if (!res.ok) throw new Error("reset failed");
-      return (await res.json()).data as ResolvedPriority;
+      return apiPut<ResolvedPriority>("/api/auth/me/source-priority", {});
     },
     onSuccess: (saved) => {
       queryClient.setQueryData(queryKeys.sourcePriority(), saved);
diff --git a/src/components/settings/telegram-card.tsx b/src/components/settings/telegram-card.tsx
index 0af940ef7..0c828fda4 100644
--- a/src/components/settings/telegram-card.tsx
+++ b/src/components/settings/telegram-card.tsx
@@ -13,6 +13,7 @@ import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { TestConnectionButton } from "@/components/settings/test-connection-button";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface TelegramSettings {
   enabled: boolean;
@@ -37,10 +38,7 @@ export function TelegramCard({
   const { data: settings } = useQuery({
     queryKey: queryKeys.telegramSettings(),
     queryFn: async () => {
-      const res = await fetch("/api/settings/telegram");
-      if (!res.ok) throw new Error("Failed");
-      const json = await res.json();
-      return json.data as TelegramSettings;
+      return apiGet<TelegramSettings>("/api/settings/telegram");
     },
     enabled: isAuthenticated,
   });
@@ -69,7 +67,7 @@ export function TelegramCard({
     if (botToken.trim()) body.botToken = botToken.trim();
     if (chatId !== (settings?.chatId ?? "")) body.chatId = chatId;
 
-    const res = await fetch("/api/settings/telegram", {
+    const res = await apiFetchRaw("/api/settings/telegram", {
       method: "PUT",
       headers: { "Content-Type": "application/json" },
       body: JSON.stringify(body),
diff --git a/src/components/settings/thresholds-editor-section.tsx b/src/components/settings/thresholds-editor-section.tsx
index 6736bacbc..ef45d8aa8 100644
--- a/src/components/settings/thresholds-editor-section.tsx
+++ b/src/components/settings/thresholds-editor-section.tsx
@@ -18,6 +18,7 @@ import {
   type ThresholdMetric,
   type EffectiveRange,
 } from "@/lib/analytics/effective-range";
+import { apiFetchRaw, apiGet } from "@/lib/api/api-fetch";
 
 interface ThresholdsApiResponse {
   effective: Record<ThresholdMetric, EffectiveRange>;
@@ -65,10 +66,7 @@ export function ThresholdsEditorSection({ id }: { id: string }) {
   const { data, isLoading } = useQuery({
     queryKey: queryKeys.userThresholds(),
     queryFn: async () => {
-      const res = await fetch("/api/user/thresholds");
-      if (!res.ok) throw new Error("failed");
-      const json = await res.json();
-      return json.data as ThresholdsApiResponse;
+      return apiGet<ThresholdsApiResponse>("/api/user/thresholds");
     },
   });
 
@@ -76,7 +74,7 @@ export function ThresholdsEditorSection({ id }: { id: string }) {
     mutationFn: async (
       payload: Partial<Record<ThresholdMetric, { min: number; max: number }>>,
     ) => {
-      const res = await fetch("/api/user/thresholds", {
+      const res = await apiFetchRaw("/api/user/thresholds", {
         method: "PUT",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify(payload),
diff --git a/src/components/settings/time-format-select.tsx b/src/components/settings/time-format-select.tsx
index 67edd7da3..11e1c851c 100644
--- a/src/components/settings/time-format-select.tsx
+++ b/src/components/settings/time-format-select.tsx
@@ -10,6 +10,7 @@ import type { TimeFormatPreference } from "@/lib/format-locale";
 import { storeTimeFormat } from "@/lib/time-format";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
 
 /**
  * Hour-cycle (12h/24h) preference as a Profile dropdown.
@@ -67,7 +68,7 @@ export function TimeFormatSelect({
 
   const mutation = useMutation({
     mutationFn: async (next: TimeFormatPreference) => {
-      const res = await fetch("/api/user/profile", {
+      const res = await apiFetchRaw("/api/user/profile", {
         method: "PATCH",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({ timeFormat: next }),
diff --git a/src/components/settings/unit-preference-select.tsx b/src/components/settings/unit-preference-select.tsx
index fa76cab1e..43a435715 100644
--- a/src/components/settings/unit-preference-select.tsx
+++ b/src/components/settings/unit-preference-select.tsx
@@ -8,6 +8,7 @@ import { NativeSelect } from "@/components/ui/native-select";
 import { useAuth } from "@/hooks/use-auth";
 import { useTranslations } from "@/lib/i18n/context";
 import { queryKeys } from "@/lib/query-keys";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
 
 type UnitPreference = "metric" | "imperial";
 
@@ -63,7 +64,7 @@ export function UnitPreferenceSelect({
 
   const mutation = useMutation({
     mutationFn: async (next: UnitPreference) => {
-      const res = await fetch("/api/auth/me/unit-preference", {
+      const res = await apiFetchRaw("/api/auth/me/unit-preference", {
         method: "PATCH",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({ unitPreference: next }),
diff --git a/src/components/settings/web-push-card.tsx b/src/components/settings/web-push-card.tsx
index c2c76fedf..c09fb7400 100644
--- a/src/components/settings/web-push-card.tsx
+++ b/src/components/settings/web-push-card.tsx
@@ -7,6 +7,7 @@ import { Button } from "@/components/ui/button";
 import { TestConnectionButton } from "@/components/settings/test-connection-button";
 import { SettingsCardHeader } from "@/components/settings/_card-header";
 import { useTranslations } from "@/lib/i18n/context";
+import { apiFetchRaw } from "@/lib/api/api-fetch";
 
 /** Convert a URL-safe base64 string to an ArrayBuffer (for VAPID key). */
 function urlBase64ToArrayBuffer(base64String: string): ArrayBuffer {
@@ -70,7 +71,7 @@ export function WebPushCard() {
     setMsgType(null);
 
     try {
-      const vapidRes = await fetch("/api/notifications/vapid");
+      const vapidRes = await apiFetchRaw("/api/notifications/vapid");
       if (!vapidRes.ok) {
         setMsg(t("settings.webPushNotConfigured"));
         setMsgType("error");
@@ -90,7 +91,7 @@ export function WebPushCard() {
 
       const subJson = subscription.toJSON();
 
-      const res = await fetch("/api/notifications/web-push", {
+      const res = await apiFetchRaw("/api/notifications/web-push", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
@@ -134,7 +135,7 @@ export function WebPushCard() {
       if (registration) {
         const subscription = await registration.pushManager.getSubscription();
         if (subscription) {
-          await fetch("/api/notifications/web-push", {
+          await apiFetchRaw("/api/notifications/web-push", {
             method: "DELETE",
             headers: { "Content-Type": "application/json" },
             body: JSON.stringify({ endpoint: subscription.endpoint }),
diff --git a/src/components/targets/consistency-strip.tsx b/src/components/targets/consistency-strip.tsx
index cfde3f643..38dda9237 100644
--- a/src/components/targets/consistency-strip.tsx
+++ b/src/components/targets/consistency-strip.tsx
@@ -24,7 +24,7 @@ import { useTranslations } from "@/lib/i18n/context";
  *
  * Hidden by the parent when the target's `insufficientData` flag is
  * true — there is no "— not enough data" empty-state mode here; the
- * card surfaces that copy in a different slot per Marc's "no empty hint
+ * card surfaces that copy in a different slot per the maintainer's "no empty hint
  * inside the strip" directive.
  *
  * Visual rationale (frontend-design skill): seven dots over the v1.4.22
diff --git a/src/components/targets/target-edit-sheet.tsx b/src/components/targets/target-edit-sheet.tsx
index 6174acf4d..c43bfec75 100644
--- a/src/components/targets/target-edit-sheet.tsx
+++ b/src/components/targets/target-edit-sheet.tsx
@@ -17,6 +17,7 @@ import {
   type EffectiveRange,
 } from "@/lib/analytics/effective-range";
 import { convertGlucose, toCanonicalMgdl } from "@/lib/glucose";
+import { apiDelete, apiGet, apiPut } from "@/lib/api/api-fetch";
 
 /**
  * Per-metric target editor, mounted inline on the Insights metric
@@ -145,10 +146,7 @@ function TargetEditSheetBody({
   const { data: thresholdsData } = useQuery({
     queryKey: ["user", "thresholds"],
     queryFn: async () => {
-      const res = await fetch("/api/user/thresholds");
-      if (!res.ok) throw new Error("failed");
-      const json = await res.json();
-      return json.data as ThresholdsApiResponse;
+      return apiGet<ThresholdsApiResponse>("/api/user/thresholds");
     },
   });
 
@@ -205,6 +203,10 @@ function TargetEditSheetBody({
   // primary input as soon as the portal paints.
   const firstInputRef = useRef<HTMLInputElement | null>(null);
   const dialogContentId = useId();
+  // v1.16.4 — the body is a real form and the footer save button
+  // associates via the `form` attribute (the footer renders in a
+  // separate slot), so Enter in any numeric field saves.
+  const formId = useId();
   useEffect(() => {
     // Defer one frame so Radix has finished placing the portal before
     // we steal focus — otherwise the focus jumps to the close-X on
@@ -222,15 +224,7 @@ function TargetEditSheetBody({
     mutationFn: async (
       payload: Partial<Record<ThresholdMetric, CurrentRange>>,
     ) => {
-      const res = await fetch("/api/user/thresholds", {
-        method: "PUT",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(payload),
-      });
-      if (!res.ok) {
-        const err = await res.json().catch(() => null);
-        throw new Error(err?.error ?? "save failed");
-      }
+      await apiPut("/api/user/thresholds", payload);
     },
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ["user", "thresholds"] });
@@ -251,18 +245,12 @@ function TargetEditSheetBody({
       if (isBp) {
         // Reset BOTH sys + dia.
         for (const m of ["BLOOD_PRESSURE_SYS", "BLOOD_PRESSURE_DIA"] as const) {
-          const res = await fetch(`/api/user/thresholds?metric=${m}`, {
-            method: "DELETE",
-          });
-          if (!res.ok) throw new Error("reset failed");
+          await apiDelete(`/api/user/thresholds?metric=${m}`);
         }
         return;
       }
       if (!metric) return;
-      const res = await fetch(`/api/user/thresholds?metric=${metric}`, {
-        method: "DELETE",
-      });
-      if (!res.ok) throw new Error("reset failed");
+      await apiDelete(`/api/user/thresholds?metric=${metric}`);
     },
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ["user", "thresholds"] });
@@ -388,8 +376,9 @@ function TargetEditSheetBody({
               {t("common.cancel")}
             </Button>
             <Button
+              type="submit"
+              form={formId}
               size="sm"
-              onClick={handleSave}
               disabled={!canSave}
               data-slot="target-edit-save"
             >
@@ -399,10 +388,15 @@ function TargetEditSheetBody({
         </div>
       }
     >
-      <div
+      <form
+        id={formId}
         data-slot="target-edit-sheet"
         data-target-type={targetType}
         aria-describedby={dialogContentId}
+        onSubmit={(e) => {
+          e.preventDefault();
+          handleSave();
+        }}
       >
         <p id={dialogContentId} className="sr-only">
           {isDerivedMetric
@@ -504,7 +498,7 @@ function TargetEditSheetBody({
             </p>
           </div>
         )}
-      </div>
+      </form>
     </ResponsiveSheet>
   );
 }
diff --git a/src/components/ui/__tests__/tabs.test.tsx b/src/components/ui/__tests__/tabs.test.tsx
index 8dce3593a..785c49966 100644
--- a/src/components/ui/__tests__/tabs.test.tsx
+++ b/src/components/ui/__tests__/tabs.test.tsx
@@ -5,7 +5,7 @@ import { Tabs, TabsList, TabsTrigger } from "../tabs";
 
 describe("<TabsList>", () => {
   it("clamps the y-axis so a fixed-height strip never paints a vertical scrollbar", () => {
-    // the maintainer reported a stray "mini scroll-button" on the right side of
+    // The maintainer reported a stray "mini scroll-button" on the right side of
     // the feedback inbox tab strip (Open / Acknowledged / Resolved /
     // Archived). Root cause: `overflow-x-auto` couples to `overflow-y`
     // — once one axis is `auto`, the other can no longer be `visible`,
diff --git a/src/components/version-poller.tsx b/src/components/version-poller.tsx
index bb8251390..df6e2bbc5 100644
--- a/src/components/version-poller.tsx
+++ b/src/components/version-poller.tsx
@@ -2,6 +2,8 @@
 
 import { useEffect } from "react";
 
+import { apiGet } from "@/lib/api/api-fetch";
+
 /**
  * v1.4.38.4 — runtime self-heal for the stale-shell post-deploy
  * paper-cut.
@@ -37,19 +39,13 @@ const POLL_INTERVAL_MS = 60_000;
 const SESSION_GUARD_KEY = "healthlog:version-reload-attempted";
 const SHELL_VERSION = process.env.NEXT_PUBLIC_APP_VERSION ?? "";
 
-type VersionEnvelope = {
-  data?: { version?: string };
-};
-
 async function fetchLiveVersion(signal: AbortSignal): Promise<string | null> {
   try {
-    const res = await fetch("/api/version", {
-      cache: "no-store",
-      signal,
-    });
-    if (!res.ok) return null;
-    const json = (await res.json()) as VersionEnvelope;
-    return json.data?.version ?? null;
+    const data = await apiGet<{ version?: string } | undefined>(
+      "/api/version",
+      { cache: "no-store", signal },
+    );
+    return data?.version ?? null;
   } catch {
     return null;
   }
diff --git a/vitest.setup.ts b/vitest.setup.ts
new file mode 100644
index 000000000..711b390fa
--- /dev/null
+++ b/vitest.setup.ts
@@ -0,0 +1,26 @@
+/**
+ * Unit-test setup.
+ *
+ * Seed the client-side locale cache with every message bundle. In
+ * production only EN ships statically; the active locale arrives as an
+ * RSC prop from the root layout and other locales load via dynamic
+ * import on switch (see `src/lib/i18n/load-locale.ts`). Tests mount
+ * `I18nProvider` standalone — often with `renderToStaticMarkup`, which
+ * is synchronous and cannot await a dynamic import — so the cache is
+ * primed up front and `t()` resolves every locale on the first render,
+ * exactly like the server-handoff path does in the app.
+ */
+import { primeMessages } from "@/lib/i18n/load-locale";
+import deMessages from "./messages/de.json";
+import enMessages from "./messages/en.json";
+import esMessages from "./messages/es.json";
+import frMessages from "./messages/fr.json";
+import itMessages from "./messages/it.json";
+import plMessages from "./messages/pl.json";
+
+primeMessages("de", deMessages);
+primeMessages("en", enMessages);
+primeMessages("es", esMessages);
+primeMessages("fr", frMessages);
+primeMessages("it", itMessages);
+primeMessages("pl", plMessages);