diff --git a/.mcp.json b/.mcp.json
new file mode 100644
index 000000000..29585572e
--- /dev/null
+++ b/.mcp.json
@@ -0,0 +1,8 @@
+{
+  "mcpServers": {
+    "shadcn": {
+      "command": "npx",
+      "args": ["-y", "shadcn@latest", "mcp"]
+    }
+  }
+}
diff --git a/docs/ui-guidelines.md b/docs/ui-guidelines.md
new file mode 100644
index 000000000..224a8c21d
--- /dev/null
+++ b/docs/ui-guidelines.md
@@ -0,0 +1,464 @@
+# HealthLog UI Guidelines
+
+> Single source of truth for visual & interaction patterns in the HealthLog
+> PWA. Consult this document before adding a new component, page, or
+> setting. If a pattern below doesn't fit your case, propose an addition
+> here in the same PR.
+
+Last updated: 2026-05-08 (v1.4 cycle)
+
+---
+
+## 1. Foundations
+
+### 1.1 Theme
+
+HealthLog is a Dracula-themed app with a light counterpart (Alucard). Both
+themes share the same six-color signal palette (purple, pink, green, cyan,
+orange, red, yellow, lavender), exposed as CSS variables and as Tailwind
+`dracula-*` color tokens. Use the semantic tokens (`--primary`,
+`--destructive`, `--card`, …) for chrome and the `--dracula-*` tokens for
+data viz only.
+
+| Surface                      | Token              |
+| ---------------------------- | ------------------ |
+| App background               | `--background`     |
+| Card / popover surface       | `--card`           |
+| Primary action               | `--primary`        |
+| Destructive action           | `--destructive`    |
+| Secondary / muted background | `--secondary`      |
+| Border                       | `--border`         |
+| Focus ring                   | `--ring`           |
+| Chart series 1–5             | `--chart-1`…`-5`   |
+| Brand signal: purple         | `--dracula-purple` |
+| Brand signal: green (good)   | `--dracula-green`  |
+| Brand signal: orange (warn)  | `--dracula-orange` |
+| Brand signal: red (alert)    | `--dracula-red`    |
+| Brand signal: cyan (info)    | `--dracula-cyan`   |
+
+Dark mode is the default. The theme switcher in the sidebar three-dot menu
+toggles `.dark` / `.light` on `:root`. Always test both modes before
+shipping a component.
+
+### 1.2 Spacing
+
+Tailwind's default 4-pixel scale. Reach for these stops first:
+
+| Use                                  | Token         | Pixels |
+| ------------------------------------ | ------------- | ------ |
+| Inline gap between icon and label    | `gap-1`       | 4      |
+| Tight stack inside a card            | `gap-2`       | 8      |
+| Default form-field stack             | `space-y-3`   | 12     |
+| Section block (heading + body)       | `space-y-4`   | 16     |
+| Page section separator               | `space-y-6`   | 24     |
+| Dashboard tile-row gap, hero spacing | `gap-4`       | 16     |
+| Page-edge padding (mobile / desktop) | `px-4 / px-6` |        |
+
+Avoid arbitrary `space-y-5`, `gap-3.5`, etc. unless aligning to a fixed
+external constraint.
+
+### 1.3 Typography
+
+The app uses the Tailwind defaults inherited via shadcn/ui. Reach for
+these classes first:
+
+| Use                                | Class                                   |
+| ---------------------------------- | --------------------------------------- |
+| Page title (h1)                    | `text-2xl font-semibold tracking-tight` |
+| Section heading (h2)               | `text-lg font-semibold`                 |
+| Card title                         | `text-base font-medium`                 |
+| Body text                          | `text-sm`                               |
+| Muted helper / metadata            | `text-sm text-muted-foreground`         |
+| Microcopy / footer                 | `text-xs text-muted-foreground`         |
+| Tabular data (latency, large nums) | `font-mono tabular-nums`                |
+
+Never use `font-bold` for emphasis — bump to `font-semibold` instead and
+let the design system breathe.
+
+### 1.4 Radius and elevation
+
+`--radius: 0.625rem` (10px) is the default. The Tailwind tokens
+`rounded-md` (`--radius-md` ≈ 8px) and `rounded-lg` (`--radius` ≈ 10px)
+cover 95% of cases. Use `rounded-2xl` only for hero cards or large
+modals.
+
+Elevation is achieved via `shadow-xs`, `shadow-sm`, or
+`shadow-[0_1px_0_rgba(255,255,255,0.04)]` for very subtle separators on
+dark backgrounds. Avoid Tailwind's heavy shadows (`shadow-lg`+) in chrome.
+
+---
+
+## 2. Components
+
+This section is **prescriptive, not exhaustive**. Each entry pairs a
+Radix/shadcn primitive with the cases it's the right answer for and the
+cases where another primitive should win.
+
+### 2.1 Buttons
+
+Every button comes from `@/components/ui/button`. Pick by purpose:
+
+| Purpose                                               | Variant       | Size              |
+| ----------------------------------------------------- | ------------- | ----------------- |
+| Primary action on a page or dialog                    | `default`     | `default`         |
+| Cancel, dismiss, secondary action next to primary     | `outline`     | `default`         |
+| Tertiary in-row action (edit, copy, snooze)           | `ghost`       | `sm`              |
+| Destructive (delete, revoke, disconnect)              | `destructive` | `default` or `sm` |
+| Icon-only action (toolbar, chart toggles, table rows) | `ghost`       | `icon-sm`         |
+| Inline link to external help docs                     | `link`        | `sm`              |
+| Toolbar / table row action when space is tight        | `outline`     | `xs`              |
+
+**Position rules.**
+
+- Forms (full-width or modal): primary on the **right**, cancel/back on
+  the **left**. Match shadcn dialog defaults.
+- Settings sections: a single sticky `Save` button at the **right end**
+  of the section header _or_ per-row inline `Save`. Never both in the
+  same section.
+- Test buttons (Telegram test, AI ping, etc.): immediately to the right
+  of the related Save / Apply control. Never below — keeps the eye
+  motion horizontal.
+- Destructive actions live in their own confirm dialog with a
+  type-to-confirm input when the action is irreversible (delete account,
+  revoke API token, drop user data).
+
+**Disabled state.** A disabled button must always come with a tooltip or
+helper text explaining why. Silent disabled buttons frustrate users.
+
+### 2.2 Inputs and forms
+
+We use `react-hook-form` + Zod schemas from `src/lib/validations/`.
+Wrap inputs in `<label>` (visible) plus `aria-describedby` for helper text.
+
+- **Text / number / email**: `<Input>`. Always set `autocomplete`. See §4.4.
+- **Multi-line**: shadcn `<Textarea>` (add via `pnpm dlx shadcn@latest add textarea` if missing).
+- **Single choice ≤4 options**: prefer `<RadioGroup>` or a SegmentedControl
+  pattern using `<Tabs>`. Never use `<Select>` for tiny enums — extra clicks.
+- **Single choice 5–15 options**: `<Select>` (shadcn).
+- **Single choice >15 options**: `<Combobox>` (shadcn `<Command>` + `<Popover>`)
+  with type-ahead.
+- **Multi choice**: `<Checkbox>` group, or shadcn `<MultiSelect>` when 7+ choices.
+- **Date / datetime**: shadcn `<Calendar>` inside a `<Popover>`. Always
+  label the timezone (Europe/Berlin).
+- **Numeric range**: `<Slider>` only when the value space is continuous
+  _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).
+
+**Validation.** Inline messages below the field. Field gets
+`aria-invalid="true"` and a destructive border. Form-level errors land
+in a `<Alert variant="destructive">` at the top. Never show a toast for
+a field-level error.
+
+### 2.3 Dialog vs Sheet vs Drawer
+
+The wrong choice here is the most visible UX mistake we make. Pick by
+intent, not by hand-feel.
+
+| Use                                                             | Primitive                      | Rationale                                                        |
+| --------------------------------------------------------------- | ------------------------------ | ---------------------------------------------------------------- |
+| Confirm a destructive or irreversible action                    | `Dialog` (`AlertDialog` shape) | Modal blocks accidental dismiss; user must read.                 |
+| Inspect a single item's details with no edit                    | `Dialog`                       | Centered, focused, dismissible.                                  |
+| Edit a single item with ≤6 fields                               | `Dialog`                       | Tight focus, quick save.                                         |
+| Edit a single item with 7+ fields, or with deep sub-sections    | `Sheet` (right)                | Wide working surface, scrollable, doesn't crop on tall content.  |
+| Mobile bottom-up sub-action (filter, sort, multi-select picker) | `Sheet` (bottom)               | Thumb-friendly, dismiss by swipe.                                |
+| Multi-step wizard                                               | Full route                     | Page transitions communicate progress better than a stuck modal. |
+| Side-by-side compare or trend deep-dive                         | Full route                     | Charts need the viewport.                                        |
+
+Never nest Dialogs. If a Dialog needs another modal action, escalate the
+inner step to a separate route or use shadcn's `<AlertDialog>` chained on
+top of a `<Sheet>`.
+
+### 2.4 Cards and lists
+
+- **Card**: a self-contained unit of content. Use `<Card>` from
+  shadcn. Header, body, footer follow Pretendard-style hierarchy.
+- **Tile**: a _small_ card showing a single metric on the dashboard.
+  See §3.2 for the one-row constraint. Tiles must include current value,
+  unit, optional sparkline, and a single tap-target area.
+- **List row**: `<div className="flex items-center justify-between gap-3 px-3 py-2 hover:bg-accent/40 rounded-md">` — left side has icon + primary
+  - meta, right side has trailing controls. Never put primary actions in
+    the right-side ellipsis menu — only secondary or destructive.
+- **Empty state**: every list and tile has an explicit empty-state
+  component with an icon, a one-sentence explanation, and a single
+  primary action ("Add measurement", "Connect Withings"). See §5.
+
+### 2.5 Tables
+
+`<Table>` (shadcn) for tabular data only — measurements list, audit log,
+admin views. Default to `<Card>` + list rows for everything else;
+tables on mobile collapse poorly. When you must use a table on mobile,
+swap to a vertical list at `sm:` breakpoint.
+
+### 2.6 Status indicators
+
+Use the same color taxonomy across the app:
+
+| State     | Color token          | Examples                                       |
+| --------- | -------------------- | ---------------------------------------------- |
+| Good      | `--dracula-green`    | Connected, in target, healthy                  |
+| Info      | `--dracula-cyan`     | Up-to-date, neutral signal                     |
+| Caution   | `--dracula-orange`   | Mildly out of range, expiring token, slow sync |
+| Alert     | `--dracula-red`      | Out of range, sync failed, critical            |
+| Pending   | `--muted-foreground` | Loading, indeterminate                         |
+| Highlight | `--dracula-purple`   | New / featured / promoted                      |
+
+Show a colored dot **plus** a label. Never rely on color alone.
+
+---
+
+## 3. Layouts
+
+### 3.1 Page shell
+
+Every authenticated page is wrapped by `<TopBar>` + `<SidebarNav>` (left)
+
+- `<BottomNav>` (mobile). Don't reinvent these on a per-page basis.
+
+* Mobile breakpoint: `<sm` shows bottom-nav, hides sidebar.
+* `sm`–`md`: sidebar in icons-only mode.
+* `md+`: sidebar full mode unless user has collapsed it
+  (`localStorage:healthlog-sidebar-collapsed`).
+
+Page content goes in `<main className="mx-auto max-w-5xl px-4 sm:px-6 py-6 space-y-6">` unless the page is a full-bleed dashboard or settings shell.
+
+### 3.2 Dashboard tiles — one-row rule
+
+Tiles at the top of the dashboard live in a **single row**. Width caps
+at the chart's width directly below. **Never** wrap to a second row.
+
+If the user enables more tiles than fit, the dashboard surfaces a banner
+inviting them to deactivate or reorder via Settings → Dashboard. The
+layout editor in Settings shows a live preview of the constraint and
+flags overflow before save.
+
+CSS: `grid-cols-N` where N = active tile count, capped by
+`Math.min(activeTiles, maxTilesForViewport(width))`. Drag-reorder via
+`@dnd-kit/sortable`. Toggle-show via the layout editor only — not in the
+tile itself, to avoid accidental hide.
+
+### 3.3 Settings — `/settings/[section]`
+
+The 1.4 release splits the legacy 3150-LOC settings monolith into one
+route per top-level section:
+
+- `/settings/account` — profile, password, passkeys, account deletion.
+- `/settings/integrations` — Withings, moodLog, Telegram, ntfy, Web Push.
+- `/settings/notifications` — channel matrix + quiet hours + reminders.
+- `/settings/dashboard` — tile layout editor, default ranges, threshold
+  overrides.
+- `/settings/ai` — AI provider selection + connection + test.
+- `/settings/api` — API tokens for headless ingest + Bearer issuance.
+- `/settings/advanced` — exports, imports, danger zone.
+- `/settings/about` — version, build, license, links to docs/changelog.
+
+Each section's component lives at `src/components/settings/<section>.tsx`
+and stays under 400 LOC. Cross-section search lives in the section
+sidebar header.
+
+The legacy `/settings` route 301-redirects to `/settings/account`.
+
+### 3.4 Admin — `/admin/[section]`
+
+Same shape as Settings, with the right-hand sidebar listing:
+
+- Users
+- Integrations status
+- Monitoring (Wide Events, GlitchTip, Umami)
+- Backups
+- Maintenance
+- Audit log
+
+Status badges use the §2.6 color taxonomy. Each section opens to a card
+grid, never a long fluid list.
+
+---
+
+## 4. Patterns
+
+### 4.1 Loading states
+
+- **Page-level**: a `<Skeleton>` matching the final layout. Never show a
+  full-screen spinner. Mount the skeleton inside the same `<main>` shell
+  the loaded page renders into.
+- **Inline**: button loading state shows a spinner + label change
+  ("Saving…", "Testing…"). Disable other form controls while pending.
+- **Long-running**: progress bar with a remaining-step count; for
+  background tasks (export, backup), surface in a toast that links to
+  the operation log instead of blocking the UI.
+
+Skeletons must respect `prefers-reduced-motion: reduce`.
+
+### 4.2 Empty states
+
+A reusable `<EmptyState>` shape:
+
+```tsx
+<EmptyState
+  icon={<Plus className="size-6" />}
+  title={t("empty.measurements.title")}
+  description={t("empty.measurements.description")}
+  action={<Button>{t("empty.measurements.add")}</Button>}
+/>
+```
+
+Every list, every chart, every dashboard tile that can be empty has an
+explicit, translated empty-state. No "No data" placeholder strings.
+
+### 4.3 Error states
+
+- **Form errors**: inline below the offending field; aggregate at the
+  top of the form for global errors (e.g. "Server unreachable").
+- **Page errors**: Next.js `error.tsx` boundaries with a friendly
+  recovery action ("Retry", "Go home"). Send the error to GlitchTip
+  through the existing client.
+- **Network errors during save**: `<Alert variant="destructive">` at
+  the top of the form _plus_ a retry button. Never silently fail.
+
+### 4.4 Forms and password managers
+
+- Measurement, medication, and mood form fields use
+  `autocomplete="off"` on every input that browsers keep guessing wrong.
+- API-token inputs and AI-provider key inputs use
+  `autocomplete="new-password"` so the browser doesn't autofill the
+  user's account password.
+- Honey-pot fields (offscreen `<input>` with `autocomplete="email"` and
+  `tabIndex={-1}`) sit at the top of measurement forms to catch
+  aggressive autofill.
+- Forms always include a hidden `<input type="text" name="username"
+autocomplete="username" value={user.email} readOnly tabIndex={-1}>`
+  inside password change and passkey screens so password managers
+  attribute saved credentials correctly.
+
+### 4.5 Test buttons (every integration)
+
+Each configurable integration ships a Test button next to its Save
+control. Behavior:
+
+- **Trigger**: ad-hoc API call to the integration with a small,
+  identifiable payload ("HealthLog test ping").
+- **State**: button shows a spinner with localized "Testing…" label.
+  Result lands inline in a `<StatusCallout>` directly below — green for
+  success with the relevant detail (last sync, message ID, response
+  status) or red for the error (sanitized message — never leak the
+  upstream URL or API key).
+- **History**: each test writes a row to a tiny per-integration log
+  visible in the section. Last 5 tests, timestamp + result.
+- **Coverage**: required for Telegram, ntfy, Web Push, AI provider,
+  Withings, moodLog, GlitchTip, Umami, email (when wired), backup
+  target. Headless E2E asserts presence + working call for each.
+
+### 4.6 Server actions and mutations
+
+We use `react-hook-form` + TanStack Query mutations, never raw fetch
+calls in components. Every mutation:
+
+1. Optimistically updates the cache with a rollback handler.
+2. Toast on success ("Saved" — translated) and on error (with retry).
+3. Re-validates queries it touches.
+
+For multi-step flows, write a typed `apiClient` helper in
+`src/lib/api/clients/` rather than re-doing fetch in three places.
+
+### 4.7 Inline help
+
+A small `?` `<Tooltip>` next to the label is the default for non-trivial
+fields (e.g. "Why does this default to ESH 2023?"). Tooltips must be
+keyboard-accessible (Radix handles this) and translated.
+
+For long explanations, link out to `https://docs.healthlog.dev/...` —
+never embed multi-paragraph help inline.
+
+---
+
+## 5. Accessibility
+
+We aim for **WCAG 2.1 AA**, with the following non-negotiables:
+
+- Color contrast ≥ 4.5:1 for normal text, 3:1 for large text and UI
+  components. Verified by `@axe-core/playwright` in CI on every page.
+- Touch targets ≥ 44×44 CSS px on bottom-nav and primary action buttons
+  (WCAG 2.5.5).
+- Focus is always visible: shadcn's `focus-visible:ring` is preserved on
+  every customized component.
+- Every interactive element has an accessible name. Icon-only buttons
+  get `<span className="sr-only">` labels and `aria-label`.
+- `prefers-reduced-motion: reduce` disables animations beyond a 200 ms
+  fade.
+- Charts include text-equivalent summaries (`aria-describedby` linked to
+  a `<p className="sr-only">` summary) and exposed data via the visible
+  legend / table view toggle.
+
+CI fails on any `serious` or `critical` axe-core violation.
+
+---
+
+## 6. Slider audit and migration
+
+Sliders look pretty but are a poor fit for most numeric inputs because
+they sacrifice precision. The 1.4 audit catalogues every `<Slider>` in
+the codebase and migrates the inappropriate ones:
+
+| Setting                             | Current control | Better control                  |
+| ----------------------------------- | --------------- | ------------------------------- |
+| Mood intensity (0–10)               | Slider          | SegmentedControl                |
+| Notification quiet-hours range      | Two sliders     | Two `<Input type="time">`       |
+| Threshold-override numeric values   | Slider          | `<Input type="number">` + steps |
+| AI insight depth (1–5 levels)       | Slider          | `<RadioGroup>` cards            |
+| Export retention days (7/30/90/365) | Slider          | `<Select>` with preset options  |
+
+A slider stays appropriate for "scrub through history" or "set chart
+zoom range" — operations where the value is continuous and live preview
+is the point.
+
+---
+
+## 7. Internationalization
+
+All user-facing strings come from `messages/en.json` (default) and
+`messages/de.json`. Use `useTranslations()` on the client and
+`getServerTranslator()` (`src/lib/i18n/server-translator.ts`) on the
+server. Numbers, dates, currencies, and units always go through
+`useFormatters()` — never hand-roll `Intl.NumberFormat(...)` with a
+fixed locale.
+
+Server-rendered content (PDFs, notifications, server-issued category
+labels) must use the locale of the user the content is for, not the
+locale of the request that triggered the job.
+
+---
+
+## 8. Motion
+
+Default transitions: `transition-all duration-150 ease-out`. Heavier
+animations (insight cards, dialog enter/exit) use the shadcn defaults.
+Reduce-motion always wins.
+
+Loading skeletons pulse via Tailwind `animate-pulse`. Don't introduce
+custom keyframes without adding a `prefers-reduced-motion` fallback.
+
+---
+
+## 9. Component checklist (for new features)
+
+Before opening a PR for a new component or page, walk through:
+
+- [ ] Uses tokens from §1, not hard-coded hex/rgba.
+- [ ] Buttons follow §2.1 variant + position rules.
+- [ ] Inputs follow §2.2; correct `autocomplete`; honey-pots where needed.
+- [ ] Dialog vs Sheet vs Drawer per §2.3.
+- [ ] Loading, empty, and error states from §4.1–4.3 implemented.
+- [ ] All strings via `t()`; numbers via formatters.
+- [ ] Mobile viewport tested (Chrome DevTools 375×667 and 414×896).
+- [ ] Light + Dark mode tested.
+- [ ] Keyboard navigation: Tab order, Enter to submit, Esc to dismiss.
+- [ ] axe-core clean (no serious/critical).
+- [ ] Headless screenshot test added if UI is non-trivial.
+
+---
+
+_Maintained as part of the v1.4 release cycle. Propose changes alongside
+the code that motivates them._
diff --git a/package.json b/package.json
index e1e569eaa..fc4182813 100644
--- a/package.json
+++ b/package.json
@@ -55,6 +55,7 @@
     "@types/react-dom": "^19",
     "@types/web-push": "^3.6.4",
     "@vitejs/plugin-react": "^5.1.4",
+    "@vitest/coverage-v8": "^4.1.5",
     "eslint": "^9",
     "eslint-config-next": "16.2.4",
     "pdf-parse": "^2.4.5",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 71506eacc..8af7b9dc1 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -19,7 +19,7 @@ importers:
         version: 7.8.0
       '@prisma/client':
         specifier: ^7.8.0
-        version: 7.8.0(prisma@7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3))(typescript@6.0.3)
+        version: 7.8.0(prisma@7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(magicast@0.5.2)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3))(typescript@6.0.3)
       '@simplewebauthn/browser':
         specifier: ^13.3.0
         version: 13.3.0
@@ -58,7 +58,7 @@ importers:
         version: 12.18.2
       prisma:
         specifier: ^7.8.0
-        version: 7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3)
+        version: 7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(magicast@0.5.2)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3)
       radix-ui:
         specifier: ^1.4.3
         version: 1.4.3(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)
@@ -108,6 +108,9 @@ importers:
       '@vitejs/plugin-react':
         specifier: ^5.1.4
         version: 5.1.4(vite@7.3.1(@types/node@25.6.0)(jiti@2.6.1)(lightningcss@1.32.0))
+      '@vitest/coverage-v8':
+        specifier: ^4.1.5
+        version: 4.1.5(vitest@4.1.5)
       eslint:
         specifier: ^9
         version: 9.39.3(jiti@2.6.1)
@@ -137,7 +140,7 @@ importers:
         version: 6.0.3
       vitest:
         specifier: ^4.1.5
-        version: 4.1.5(@types/node@25.6.0)(msw@2.14.2(@types/node@25.6.0)(typescript@6.0.3))(vite@7.3.1(@types/node@25.6.0)(jiti@2.6.1)(lightningcss@1.32.0))
+        version: 4.1.5(@types/node@25.6.0)(@vitest/coverage-v8@4.1.5)(msw@2.14.2(@types/node@25.6.0)(typescript@6.0.3))(vite@7.3.1(@types/node@25.6.0)(jiti@2.6.1)(lightningcss@1.32.0))
 
 packages:
 
@@ -290,6 +293,10 @@ packages:
     resolution: {integrity: sha512-LwdZHpScM4Qz8Xw2iKSzS+cfglZzJGvofQICy7W7v4caru4EaAmyUuO6BGrbyQ2mYV11W0U8j5mBhd14dd3B0A==}
     engines: {node: '>=6.9.0'}
 
+  '@bcoe/v8-coverage@1.0.2':
+    resolution: {integrity: sha512-6zABk/ECA/QYSCQ1NGiVwwbQerUCZ+TQbp64Q3AgmfNvurHH0j8TtXa1qbShXA6qqkpAj4V5W8pP6mLe1mcMqA==}
+    engines: {node: '>=18'}
+
   '@dotenvx/dotenvx@1.64.0':
     resolution: {integrity: sha512-6+xRpZaWuHXEqnhBjae+VmQI9Uaqw5Uzu/ScpO+W7ww9Zp3lHSNBoNjFcUxhrCyc7pRGQzyDjhKzloqrPHERiQ==}
     hasBin: true
@@ -2390,6 +2397,15 @@ packages:
     peerDependencies:
       vite: ^4.2.0 || ^5.0.0 || ^6.0.0 || ^7.0.0
 
+  '@vitest/coverage-v8@4.1.5':
+    resolution: {integrity: sha512-38C0/Ddb7HcRG0Z4/DUem8x57d2p9jYgp18mkaYswEOQBGsI1CG4f/hjm0ZCeaJfWhSZ4k7jgs29V1Zom7Ki9A==}
+    peerDependencies:
+      '@vitest/browser': 4.1.5
+      vitest: 4.1.5
+    peerDependenciesMeta:
+      '@vitest/browser':
+        optional: true
+
   '@vitest/expect@4.1.5':
     resolution: {integrity: sha512-PWBaRY5JoKuRnHlUHfpV/KohFylaDZTupcXN1H9vYryNLOnitSw60Mw9IAE2r67NbwwzBw/Cc/8q9BK3kIX8Kw==}
 
@@ -2524,6 +2540,9 @@ packages:
     resolution: {integrity: sha512-6t10qk83GOG8p0vKmaCr8eiilZwO171AvbROMtvvNiwrTly62t+7XkA8RdIIVbpMhCASAsxgAzdRSwh6nw/5Dg==}
     engines: {node: '>=4'}
 
+  ast-v8-to-istanbul@1.0.0:
+    resolution: {integrity: sha512-1fSfIwuDICFA4LKkCzRPO7F0hzFf0B7+Xqrl27ynQaa+Rh0e1Es0v6kWHPott3lU10AyAr7oKHa65OppjLn3Rg==}
+
   async-function@1.0.0:
     resolution: {integrity: sha512-hsU18Ae8CDTR6Kgu9DYf0EbCr/a5iGL0rytQDobUcdpYOKokk8LEjVphnXkDkgpi0wYVsqrXuP0bZxJaTqdgoA==}
     engines: {node: '>= 0.4'}
@@ -3461,6 +3480,9 @@ packages:
     resolution: {integrity: sha512-jN0ZewiNAWSe5khM3EyCmBb250+b40wWbwNILNfEvq84VREWwOIkuUsFONk/3i3nqkz7Oe1PcpM2mwQEK2L9Kg==}
     engines: {node: '>=16.9.0'}
 
+  html-escaper@2.0.2:
+    resolution: {integrity: sha512-H2iMtd0I4Mt5eYiapRdIDjp+XzelXQ0tFE4JS7YFwFevXXMmOp9myNrUvCg0D6ws8iqkRPBfKHgbwig1SmlLfg==}
+
   html2canvas@1.4.1:
     resolution: {integrity: sha512-fPU6BHNpsyIhr8yyMpTLLxAbkaK8ArIBcmZIRiBLiDhjeqvXolaEmDGmELFuX9I4xDcaKKcJl+TKZLqruBbmWA==}
     engines: {node: '>=8.0.0'}
@@ -3715,6 +3737,18 @@ packages:
     resolution: {integrity: sha512-6B3tLtFqtQS4ekarvLVMZ+X+VlvQekbe4taUkf/rhVO3d/h0M2rfARm/pXLcPEsjjMsFgrFgSrhQIxcSVrBz8w==}
     engines: {node: '>=18'}
 
+  istanbul-lib-coverage@3.2.2:
+    resolution: {integrity: sha512-O8dpsF+r0WV/8MNRKfnmrtCWhuKjxrq2w+jpzBL5UZKTi2LeVWnWOmWRxFlesJONmc+wLAGvKQZEOanko0LFTg==}
+    engines: {node: '>=8'}
+
+  istanbul-lib-report@3.0.1:
+    resolution: {integrity: sha512-GCfE1mtsHGOELCU8e/Z7YWzpmybrx/+dSTfLrvY8qRmaY6zXTKWn6WQIjaAFw069icm6GVMNkgu0NzI4iPZUNw==}
+    engines: {node: '>=10'}
+
+  istanbul-reports@3.2.0:
+    resolution: {integrity: sha512-HGYWWS/ehqTV3xN10i23tkPkpH46MLCIMFNCaaKNavAXTF1RkqxawEPtnjnGZ6XKSInBKkiOA5BKS+aZiY3AvA==}
+    engines: {node: '>=8'}
+
   iterator.prototype@1.1.5:
     resolution: {integrity: sha512-H0dkQoCa3b2VEeKQBOxFph+JAbcrQdE7KC0UkqwpLmv2EC4P41QXP+rqo9wYodACiG5/WM5s9oDApTU8utwj9g==}
     engines: {node: '>= 0.4'}
@@ -3726,6 +3760,9 @@ packages:
   jose@6.2.3:
     resolution: {integrity: sha512-YYVDInQKFJfR/xa3ojUTl8c2KoTwiL1R5Wg9YCydwH0x0B9grbzlg5HC7mMjCtUJjbQ/YnGEZIhI5tCgfTb4Hw==}
 
+  js-tokens@10.0.0:
+    resolution: {integrity: sha512-lM/UBzQmfJRo9ABXbPWemivdCW8V2G8FHaHdypQaIy523snUjog0W71ayWXTjiR+ixeMyVHN2XcpnTd/liPg/Q==}
+
   js-tokens@4.0.0:
     resolution: {integrity: sha512-RdJUflcE3cUzKiMqQgsCu06FPu9UdIJO0beYbPhHN4k6apgJtifcoCtT9bcxOpYBtpD2kCM6Sbzg4CausW/PKQ==}
 
@@ -3922,6 +3959,13 @@ packages:
   magic-string@0.30.21:
     resolution: {integrity: sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ==}
 
+  magicast@0.5.2:
+    resolution: {integrity: sha512-E3ZJh4J3S9KfwdjZhe2afj6R9lGIN5Pher1pF39UGrXRqq/VDaGVIGN13BjHd2u8B61hArAGOnso7nBOouW3TQ==}
+
+  make-dir@4.0.0:
+    resolution: {integrity: sha512-hXdUTZYIVOt1Ex//jAQi+wTZZpUpwBj/0QsOzqegb3rGMMeJiSEu5xLHnYfBrRV4RH2+OCSOO95Is/7x1WJ4bw==}
+    engines: {node: '>=10'}
+
   math-intrinsics@1.1.0:
     resolution: {integrity: sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g==}
     engines: {node: '>= 0.4'}
@@ -5479,6 +5523,8 @@ snapshots:
       '@babel/helper-string-parser': 7.27.1
       '@babel/helper-validator-identifier': 7.28.5
 
+  '@bcoe/v8-coverage@1.0.2': {}
+
   '@dotenvx/dotenvx@1.64.0':
     dependencies:
       commander: 11.1.0
@@ -6153,16 +6199,16 @@ snapshots:
 
   '@prisma/client-runtime-utils@7.8.0': {}
 
-  '@prisma/client@7.8.0(prisma@7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3))(typescript@6.0.3)':
+  '@prisma/client@7.8.0(prisma@7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(magicast@0.5.2)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3))(typescript@6.0.3)':
     dependencies:
       '@prisma/client-runtime-utils': 7.8.0
     optionalDependencies:
-      prisma: 7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3)
+      prisma: 7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(magicast@0.5.2)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3)
       typescript: 6.0.3
 
-  '@prisma/config@7.8.0':
+  '@prisma/config@7.8.0(magicast@0.5.2)':
     dependencies:
-      c12: 3.3.4
+      c12: 3.3.4(magicast@0.5.2)
       deepmerge-ts: 7.1.5
       effect: 3.20.0
       empathic: 2.0.0
@@ -7451,6 +7497,20 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
+  '@vitest/coverage-v8@4.1.5(vitest@4.1.5)':
+    dependencies:
+      '@bcoe/v8-coverage': 1.0.2
+      '@vitest/utils': 4.1.5
+      ast-v8-to-istanbul: 1.0.0
+      istanbul-lib-coverage: 3.2.2
+      istanbul-lib-report: 3.0.1
+      istanbul-reports: 3.2.0
+      magicast: 0.5.2
+      obug: 2.1.1
+      std-env: 4.1.0
+      tinyrainbow: 3.1.0
+      vitest: 4.1.5(@types/node@25.6.0)(@vitest/coverage-v8@4.1.5)(msw@2.14.2(@types/node@25.6.0)(typescript@6.0.3))(vite@7.3.1(@types/node@25.6.0)(jiti@2.6.1)(lightningcss@1.32.0))
+
   '@vitest/expect@4.1.5':
     dependencies:
       '@standard-schema/spec': 1.1.0
@@ -7628,6 +7688,12 @@ snapshots:
     dependencies:
       tslib: 2.8.1
 
+  ast-v8-to-istanbul@1.0.0:
+    dependencies:
+      '@jridgewell/trace-mapping': 0.3.31
+      estree-walker: 3.0.3
+      js-tokens: 10.0.0
+
   async-function@1.0.0: {}
 
   available-typed-arrays@1.0.7:
@@ -7703,7 +7769,7 @@ snapshots:
 
   bytes@3.1.2: {}
 
-  c12@3.3.4:
+  c12@3.3.4(magicast@0.5.2):
     dependencies:
       chokidar: 5.0.0
       confbox: 0.2.4
@@ -7717,6 +7783,8 @@ snapshots:
       perfect-debounce: 2.1.0
       pkg-types: 2.3.0
       rc9: 3.0.1
+    optionalDependencies:
+      magicast: 0.5.2
 
   call-bind-apply-helpers@1.0.2:
     dependencies:
@@ -8713,6 +8781,8 @@ snapshots:
 
   hono@4.12.16: {}
 
+  html-escaper@2.0.2: {}
+
   html2canvas@1.4.1:
     dependencies:
       css-line-break: 2.1.0
@@ -8933,6 +9003,19 @@ snapshots:
 
   isexe@3.1.5: {}
 
+  istanbul-lib-coverage@3.2.2: {}
+
+  istanbul-lib-report@3.0.1:
+    dependencies:
+      istanbul-lib-coverage: 3.2.2
+      make-dir: 4.0.0
+      supports-color: 7.2.0
+
+  istanbul-reports@3.2.0:
+    dependencies:
+      html-escaper: 2.0.2
+      istanbul-lib-report: 3.0.1
+
   iterator.prototype@1.1.5:
     dependencies:
       define-data-property: 1.1.4
@@ -8946,6 +9029,8 @@ snapshots:
 
   jose@6.2.3: {}
 
+  js-tokens@10.0.0: {}
+
   js-tokens@4.0.0: {}
 
   js-yaml@4.1.1:
@@ -9114,6 +9199,16 @@ snapshots:
     dependencies:
       '@jridgewell/sourcemap-codec': 1.5.5
 
+  magicast@0.5.2:
+    dependencies:
+      '@babel/parser': 7.29.3
+      '@babel/types': 7.29.0
+      source-map-js: 1.2.1
+
+  make-dir@4.0.0:
+    dependencies:
+      semver: 7.7.4
+
   math-intrinsics@1.1.0: {}
 
   media-typer@1.1.0: {}
@@ -9534,9 +9629,9 @@ snapshots:
     dependencies:
       parse-ms: 4.0.0
 
-  prisma@7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3):
+  prisma@7.8.0(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(magicast@0.5.2)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)(typescript@6.0.3):
     dependencies:
-      '@prisma/config': 7.8.0
+      '@prisma/config': 7.8.0(magicast@0.5.2)
       '@prisma/dev': 0.24.3(typescript@6.0.3)
       '@prisma/engines': 7.8.0
       '@prisma/studio-core': 0.27.3(@types/react-dom@19.2.3(@types/react@19.2.14))(@types/react@19.2.14)(react-dom@19.2.5(react@19.2.5))(react@19.2.5)
@@ -10454,7 +10549,7 @@ snapshots:
       jiti: 2.6.1
       lightningcss: 1.32.0
 
-  vitest@4.1.5(@types/node@25.6.0)(msw@2.14.2(@types/node@25.6.0)(typescript@6.0.3))(vite@7.3.1(@types/node@25.6.0)(jiti@2.6.1)(lightningcss@1.32.0)):
+  vitest@4.1.5(@types/node@25.6.0)(@vitest/coverage-v8@4.1.5)(msw@2.14.2(@types/node@25.6.0)(typescript@6.0.3))(vite@7.3.1(@types/node@25.6.0)(jiti@2.6.1)(lightningcss@1.32.0)):
     dependencies:
       '@vitest/expect': 4.1.5
       '@vitest/mocker': 4.1.5(msw@2.14.2(@types/node@25.6.0)(typescript@6.0.3))(vite@7.3.1(@types/node@25.6.0)(jiti@2.6.1)(lightningcss@1.32.0))
@@ -10478,6 +10573,7 @@ snapshots:
       why-is-node-running: 2.3.0
     optionalDependencies:
       '@types/node': 25.6.0
+      '@vitest/coverage-v8': 4.1.5(vitest@4.1.5)
     transitivePeerDependencies:
       - msw
 
diff --git a/src/app/api/ai/test/__tests__/route.test.ts b/src/app/api/ai/test/__tests__/route.test.ts
index d72c2912d..2fa230aec 100644
--- a/src/app/api/ai/test/__tests__/route.test.ts
+++ b/src/app/api/ai/test/__tests__/route.test.ts
@@ -3,12 +3,22 @@ import { describe, it, expect, vi, beforeEach } from "vitest";
 // Mocks must be hoisted before importing the route.
 vi.mock("@/lib/api-handler", () => ({
   apiHandler: <T extends (...args: unknown[]) => unknown>(fn: T) => fn,
-  requireAuth: vi.fn(async () => ({ user: { id: "u-1" }, session: { id: "s-1" } })),
+  requireAuth: vi.fn(async () => ({
+    user: { id: "u-1" },
+    session: { id: "s-1" },
+  })),
 }));
 
-vi.mock("@/lib/ai/provider", () => ({
-  resolveProvider: vi.fn(),
-}));
+vi.mock("@/lib/ai/provider", async () => {
+  const actual =
+    await vi.importActual<typeof import("@/lib/ai/provider")>(
+      "@/lib/ai/provider",
+    );
+  return {
+    ...actual,
+    resolveProviderForTest: vi.fn(),
+  };
+});
 
 vi.mock("@/lib/rate-limit", () => ({
   checkRateLimit: vi.fn(async () => ({ allowed: true })),
@@ -19,10 +29,11 @@ vi.mock("@/lib/logging/context", () => ({
 }));
 
 import { POST } from "../route";
-import { resolveProvider } from "@/lib/ai/provider";
+import { resolveProviderForTest } from "@/lib/ai/provider";
 
 beforeEach(() => {
   vi.resetAllMocks();
+  vi.mocked(resolveProviderForTest).mockReset();
 });
 
 interface ApiErrorEnvelope {
@@ -30,6 +41,30 @@ interface ApiErrorEnvelope {
   error: string;
 }
 
+interface ApiSuccessEnvelope<T> {
+  data: T;
+  error: null;
+}
+
+function emptyRequest(): Request {
+  return new Request("http://localhost/api/ai/test", {
+    method: "POST",
+    headers: { "content-length": "0" },
+  });
+}
+
+function jsonRequest(body: unknown): Request {
+  const text = JSON.stringify(body);
+  return new Request("http://localhost/api/ai/test", {
+    method: "POST",
+    headers: {
+      "content-type": "application/json",
+      "content-length": String(text.length),
+    },
+    body: text,
+  });
+}
+
 // V3 audit: /api/ai/test was returning provider err.message + bodyExcerpt
 // directly to the client, leaking provider URLs / partial keys / internal
 // headers. Server now logs full details via annotate() and responds with
@@ -38,7 +73,7 @@ describe("POST /api/ai/test — provider error leak guard", () => {
   function makeProviderThatThrows(
     err: Error & { httpStatus?: number; bodyExcerpt?: string },
   ) {
-    vi.mocked(resolveProvider).mockResolvedValue({
+    vi.mocked(resolveProviderForTest).mockResolvedValue({
       type: "openai",
       generateCompletion: vi.fn(async () => {
         throw err;
@@ -49,11 +84,14 @@ describe("POST /api/ai/test — provider error leak guard", () => {
   it("does not echo provider err.message back to the client (HIGH coverage gap)", async () => {
     const err = Object.assign(
       new Error("OpenAI 401 from https://api.openai.com/v1 sk-leaked-key"),
-      { httpStatus: 401 as const, bodyExcerpt: '{"error":"invalid api key sk-secret"}' },
+      {
+        httpStatus: 401 as const,
+        bodyExcerpt: '{"error":"invalid api key sk-secret"}',
+      },
     );
     makeProviderThatThrows(err);
 
-    const response = await POST();
+    const response = await POST(emptyRequest() as never);
     const body = (await response.json()) as ApiErrorEnvelope;
 
     expect(response.status).toBe(502);
@@ -67,7 +105,7 @@ describe("POST /api/ai/test — provider error leak guard", () => {
     makeProviderThatThrows(
       Object.assign(new Error("429 from openai"), { httpStatus: 429 as const }),
     );
-    const response = await POST();
+    const response = await POST(emptyRequest() as never);
     expect(response.status).toBe(502);
     expect(((await response.json()) as ApiErrorEnvelope).error).toBe(
       "Provider rate-limited the request",
@@ -78,7 +116,7 @@ describe("POST /api/ai/test — provider error leak guard", () => {
     makeProviderThatThrows(
       Object.assign(new Error("503 upstream"), { httpStatus: 503 as const }),
     );
-    const response = await POST();
+    const response = await POST(emptyRequest() as never);
     expect(((await response.json()) as ApiErrorEnvelope).error).toBe(
       "Provider returned a server error",
     );
@@ -86,9 +124,76 @@ describe("POST /api/ai/test — provider error leak guard", () => {
 
   it("returns the unknown-error fallback otherwise", async () => {
     makeProviderThatThrows(new Error("ECONNRESET"));
-    const response = await POST();
+    const response = await POST(emptyRequest() as never);
     expect(((await response.json()) as ApiErrorEnvelope).error).toBe(
       "Provider connection failed",
     );
   });
 });
+
+// v1.4 fix: the dropdown in /settings was not honoured — the test always
+// ran against the SAVED provider (Marc reported "wirft was Komisches raus").
+// The route now accepts a JSON override body and forwards the user's
+// unsaved selection to resolveProviderForTest().
+describe("POST /api/ai/test — dropdown-aware override", () => {
+  function makeProviderThatSucceeds(model: string) {
+    vi.mocked(resolveProviderForTest).mockResolvedValue({
+      type: "anthropic",
+      generateCompletion: vi.fn(async () => ({
+        content: '{"ok":true}',
+        providerType: "anthropic",
+        model,
+        tokensUsed: 5,
+      })),
+    } as never);
+  }
+
+  it("forwards a dropdown override to resolveProviderForTest", async () => {
+    makeProviderThatSucceeds("claude-3-5-sonnet-latest");
+    const response = await POST(
+      jsonRequest({
+        provider: "ANTHROPIC",
+        model: "claude-3-5-sonnet-latest",
+      }) as never,
+    );
+    expect(response.status).toBe(200);
+    expect(resolveProviderForTest).toHaveBeenCalledWith("u-1", {
+      provider: "ANTHROPIC",
+      model: "claude-3-5-sonnet-latest",
+    });
+    const body = (await response.json()) as ApiSuccessEnvelope<{
+      providerType: string;
+      model: string;
+    }>;
+    expect(body.data.providerType).toBe("anthropic");
+    expect(body.data.model).toBe("claude-3-5-sonnet-latest");
+  });
+
+  it("rejects unknown provider values with 422", async () => {
+    const response = await POST(
+      jsonRequest({ provider: "MALICIOUS" }) as never,
+    );
+    expect(response.status).toBe(422);
+    expect(resolveProviderForTest).not.toHaveBeenCalled();
+  });
+
+  it("uses the persisted config when the body is empty", async () => {
+    makeProviderThatSucceeds("claude-3-5-sonnet-latest");
+    const response = await POST(emptyRequest() as never);
+    expect(response.status).toBe(200);
+    expect(resolveProviderForTest).toHaveBeenCalledWith("u-1", {});
+  });
+
+  it("surfaces config errors as the same status as the resolver throws", async () => {
+    const { AITestConfigError } = await import("@/lib/ai/provider");
+    vi.mocked(resolveProviderForTest).mockRejectedValueOnce(
+      new AITestConfigError(422, "Anthropic API key not configured"),
+    );
+    const response = await POST(
+      jsonRequest({ provider: "ANTHROPIC" }) as never,
+    );
+    expect(response.status).toBe(422);
+    const body = (await response.json()) as ApiErrorEnvelope;
+    expect(body.error).toBe("Anthropic API key not configured");
+  });
+});
diff --git a/src/app/api/ai/test/route.ts b/src/app/api/ai/test/route.ts
index de6385bf4..79057c945 100644
--- a/src/app/api/ai/test/route.ts
+++ b/src/app/api/ai/test/route.ts
@@ -1,19 +1,62 @@
+import type { NextRequest } from "next/server";
+import { z } from "zod/v4";
 import { apiHandler, requireAuth } from "@/lib/api-handler";
-import { resolveProvider } from "@/lib/ai/provider";
-import { apiSuccess, apiError } from "@/lib/api-response";
+import {
+  resolveProviderForTest,
+  AITestConfigError,
+  type AITestOverride,
+} from "@/lib/ai/provider";
+import { apiSuccess, apiError, safeJson } from "@/lib/api-response";
 import { checkRateLimit } from "@/lib/rate-limit";
 import { annotate } from "@/lib/logging/context";
 
 export const dynamic = "force-dynamic";
 
-export const POST = apiHandler(async () => {
+const overrideSchema = z
+  .object({
+    provider: z
+      .enum(["OPENAI", "ANTHROPIC", "LOCAL", "CHATGPT_OAUTH"])
+      .optional()
+      .nullable(),
+    model: z.string().min(1).max(120).optional().nullable(),
+    baseUrl: z.string().url().max(2048).optional().nullable(),
+    anthropicKey: z.string().min(1).max(500).optional().nullable(),
+    localKey: z.string().min(1).max(500).optional().nullable(),
+  })
+  .strict();
+
+export const POST = apiHandler(async (request: NextRequest) => {
   const { user } = await requireAuth();
   annotate({ action: { name: "ai.test" } });
 
   const rl = await checkRateLimit(`ai-test:${user.id}`, 5, 60_000);
   if (!rl.allowed) return apiError("Too many test requests", 429);
 
-  const provider = await resolveProvider(user.id);
+  // Body is optional. Empty body → behaves like before (test the saved
+  // config). Non-empty body → tests the unsaved selection without
+  // mutating the user row. Plaintext keys never persist.
+  let override: AITestOverride = {};
+  const contentLength = Number(request.headers.get("content-length") ?? "0");
+  if (contentLength > 0) {
+    const { data, error } = await safeJson<unknown>(request);
+    if (error) return error;
+    const parsed = overrideSchema.safeParse(data);
+    if (!parsed.success) {
+      return apiError("Invalid override payload", 422);
+    }
+    override = parsed.data;
+  }
+
+  let provider;
+  try {
+    provider = await resolveProviderForTest(user.id, override);
+  } catch (e) {
+    if (e instanceof AITestConfigError) {
+      return apiError(e.message, e.status);
+    }
+    throw e;
+  }
+
   if (provider.type === "none") {
     return apiError("No AI provider configured", 422);
   }
diff --git a/src/app/settings/page.tsx b/src/app/settings/page.tsx
index 89b83d894..33d474d1c 100644
--- a/src/app/settings/page.tsx
+++ b/src/app/settings/page.tsx
@@ -297,383 +297,387 @@ export default function SettingsPage() {
         </p>
       </div>
 
-        {user.role === "ADMIN" && (
-          <div className="bg-card border-border mb-6 rounded-xl border p-6">
-            <div className="flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
-              <div>
-                <div className="flex items-center gap-2">
-                  <Shield className="text-primary h-5 w-5" />
-                  <h2 className="text-lg font-semibold">
-                    {t("settings.adminAreaTitle")}
-                  </h2>
-                </div>
-                <p className="text-muted-foreground text-sm">
-                  {t("settings.adminAreaDescription")}
-                </p>
-              </div>
-              <Button asChild variant="outline">
-                <Link href="/admin">
-                  <Shield className="mr-2 h-4 w-4" />
-                  {t("settings.openAdminConsole")}
-                </Link>
-              </Button>
-            </div>
-          </div>
-        )}
-
-        <div className="space-y-8">
-          <section id="section-allgemein" className="scroll-mt-28 space-y-3">
-            <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
-              {t("settings.categoryGeneral")}
-            </h2>
-
-            {/* Profile Section */}
-            <div
-              id="profil"
-              className="bg-card border-border rounded-xl border p-6"
-            >
-              <div className="mb-4 flex items-center gap-2">
-                <User className="text-primary h-5 w-5" />
+      {user.role === "ADMIN" && (
+        <div className="bg-card border-border mb-6 rounded-xl border p-6">
+          <div className="flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
+            <div>
+              <div className="flex items-center gap-2">
+                <Shield className="text-primary h-5 w-5" />
                 <h2 className="text-lg font-semibold">
-                  {t("settings.profile")}
+                  {t("settings.adminAreaTitle")}
                 </h2>
               </div>
-              <form onSubmit={handleSaveProfile} className="space-y-4">
-                <div className="grid gap-4 sm:grid-cols-2">
-                  <div className="space-y-2">
-                    <Label htmlFor="username">{t("settings.username")}</Label>
-                    <Input id="username" value={user.username} disabled />
-                  </div>
-                  <div className="space-y-2">
-                    <Label htmlFor="email">{t("auth.email")}</Label>
-                    <Input
-                      id="email"
-                      type="email"
-                      value={email}
-                      onChange={(e) => setEmail(e.target.value)}
-                      placeholder={t("auth.emailPlaceholder")}
-                      maxLength={320}
-                    />
-                  </div>
-                </div>
+              <p className="text-muted-foreground text-sm">
+                {t("settings.adminAreaDescription")}
+              </p>
+            </div>
+            <Button asChild variant="outline">
+              <Link href="/admin">
+                <Shield className="mr-2 h-4 w-4" />
+                {t("settings.openAdminConsole")}
+              </Link>
+            </Button>
+          </div>
+        </div>
+      )}
 
-                <div className="grid gap-4 sm:grid-cols-2">
-                  <div className="space-y-2">
-                    <Label htmlFor="gender">{t("settings.gender")}</Label>
-                    <select
-                      id="gender"
-                      value={gender}
-                      onChange={(e) => setGender(e.target.value)}
-                      className="border-input bg-background text-foreground ring-offset-background placeholder:text-muted-foreground focus-visible:ring-ring flex h-9 w-full rounded-md border px-3 py-1 text-sm focus-visible:ring-2 focus-visible:ring-offset-2 focus-visible:outline-none"
-                    >
-                      <option value="">{t("settings.genderNone")}</option>
-                      <option value="MALE">{t("settings.genderMale")}</option>
-                      <option value="FEMALE">
-                        {t("settings.genderFemale")}
+      <div className="space-y-8">
+        <section id="section-allgemein" className="scroll-mt-28 space-y-3">
+          <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
+            {t("settings.categoryGeneral")}
+          </h2>
+
+          {/* Profile Section */}
+          <div
+            id="profil"
+            className="bg-card border-border rounded-xl border p-6"
+          >
+            <div className="mb-4 flex items-center gap-2">
+              <User className="text-primary h-5 w-5" />
+              <h2 className="text-lg font-semibold">{t("settings.profile")}</h2>
+            </div>
+            <form onSubmit={handleSaveProfile} className="space-y-4">
+              <div className="grid gap-4 sm:grid-cols-2">
+                <div className="space-y-2">
+                  <Label htmlFor="username">{t("settings.username")}</Label>
+                  <Input id="username" value={user.username} disabled />
+                </div>
+                <div className="space-y-2">
+                  <Label htmlFor="email">{t("auth.email")}</Label>
+                  <Input
+                    id="email"
+                    type="email"
+                    value={email}
+                    onChange={(e) => setEmail(e.target.value)}
+                    placeholder={t("auth.emailPlaceholder")}
+                    maxLength={320}
+                  />
+                </div>
+              </div>
+
+              <div className="grid gap-4 sm:grid-cols-2">
+                <div className="space-y-2">
+                  <Label htmlFor="gender">{t("settings.gender")}</Label>
+                  <select
+                    id="gender"
+                    value={gender}
+                    onChange={(e) => setGender(e.target.value)}
+                    className="border-input bg-background text-foreground ring-offset-background placeholder:text-muted-foreground focus-visible:ring-ring flex h-9 w-full rounded-md border px-3 py-1 text-sm focus-visible:ring-2 focus-visible:ring-offset-2 focus-visible:outline-none"
+                  >
+                    <option value="">{t("settings.genderNone")}</option>
+                    <option value="MALE">{t("settings.genderMale")}</option>
+                    <option value="FEMALE">{t("settings.genderFemale")}</option>
+                  </select>
+                  <p className="text-muted-foreground text-xs">
+                    {t("settings.genderHint")}
+                  </p>
+                </div>
+                <div className="space-y-2">
+                  <Label htmlFor="height">{t("settings.height")}</Label>
+                  <Input
+                    id="height"
+                    type="number"
+                    value={heightCm}
+                    onChange={(e) => setHeightCm(e.target.value)}
+                    placeholder="175"
+                    min={50}
+                    max={300}
+                    step={0.1}
+                  />
+                </div>
+              </div>
+
+              <div className="grid gap-4 sm:grid-cols-2">
+                <div className="space-y-2">
+                  <Label htmlFor="dob">{t("settings.dateOfBirth")}</Label>
+                  <Input
+                    id="dob"
+                    type="date"
+                    value={dateOfBirth}
+                    onChange={(e) => setDateOfBirth(e.target.value)}
+                    max={new Date().toISOString().slice(0, 10)}
+                  />
+                  <p className="text-muted-foreground text-xs">
+                    {t("settings.dateOfBirthHint")}
+                  </p>
+                </div>
+                <div className="space-y-2">
+                  <Label htmlFor="language-select">
+                    {t("settings.language")}
+                  </Label>
+                  <select
+                    id="language-select"
+                    value={locale}
+                    onChange={(e) => setLocale(e.target.value as Locale)}
+                    className="border-input bg-background text-foreground ring-offset-background focus-visible:ring-ring flex h-9 w-full rounded-md border px-3 py-1 text-sm focus-visible:ring-2 focus-visible:ring-offset-2 focus-visible:outline-none"
+                  >
+                    {locales.map((loc) => (
+                      <option key={loc} value={loc}>
+                        {localeLabels[loc as Locale]}
                       </option>
-                    </select>
-                    <p className="text-muted-foreground text-xs">
-                      {t("settings.genderHint")}
-                    </p>
-                  </div>
-                  <div className="space-y-2">
-                    <Label htmlFor="height">{t("settings.height")}</Label>
-                    <Input
-                      id="height"
-                      type="number"
-                      value={heightCm}
-                      onChange={(e) => setHeightCm(e.target.value)}
-                      placeholder="175"
-                      min={50}
-                      max={300}
-                      step={0.1}
-                    />
-                  </div>
+                    ))}
+                  </select>
+                  <p className="text-muted-foreground text-xs">
+                    {t("settings.languageDescription")}
+                  </p>
                 </div>
+              </div>
 
-                <div className="grid gap-4 sm:grid-cols-2">
-                  <div className="space-y-2">
-                    <Label htmlFor="dob">{t("settings.dateOfBirth")}</Label>
-                    <Input
-                      id="dob"
-                      type="date"
-                      value={dateOfBirth}
-                      onChange={(e) => setDateOfBirth(e.target.value)}
-                      max={new Date().toISOString().slice(0, 10)}
-                    />
-                    <p className="text-muted-foreground text-xs">
-                      {t("settings.dateOfBirthHint")}
-                    </p>
-                  </div>
-                  <div className="space-y-2">
-                    <Label htmlFor="language-select">
-                      {t("settings.language")}
+              {saveMsg && (
+                <p
+                  role="alert"
+                  className={`text-sm ${
+                    saveMsgType === "success"
+                      ? "text-dracula-green"
+                      : "text-destructive"
+                  }`}
+                >
+                  {saveMsg}
+                </p>
+              )}
+
+              <div className="flex justify-end">
+                <Button type="submit" disabled={saving}>
+                  {saving ? (
+                    <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+                  ) : (
+                    <Save className="mr-2 h-4 w-4" />
+                  )}
+                  {t("common.save")}
+                </Button>
+              </div>
+            </form>
+          </div>
+        </section>
+
+        <section id="section-sicherheit" className="scroll-mt-28 space-y-3">
+          <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
+            {t("settings.security")}
+          </h2>
+
+          <div
+            id="passkeys"
+            className="bg-card border-border scroll-mt-28 rounded-xl border p-6"
+          >
+            <div className="mb-4 flex items-center gap-2">
+              <Shield className="text-primary h-5 w-5" />
+              <h2 className="text-lg font-semibold">
+                {t("settings.passkeys")}
+              </h2>
+            </div>
+            <PasskeyListSection isAuthenticated={isAuthenticated} />
+            <div className="mt-4 flex justify-end">
+              <Button
+                variant="outline"
+                onClick={handleAddPasskey}
+                disabled={passkeyLoading}
+              >
+                {passkeyLoading ? (
+                  <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+                ) : (
+                  <KeyRound className="mr-2 h-4 w-4" />
+                )}
+                {t("settings.addPasskey")}
+              </Button>
+              {passkeyMsg && (
+                <p
+                  role="alert"
+                  className={`mt-2 text-sm ${
+                    passkeyMsgType === "success"
+                      ? "text-dracula-green"
+                      : "text-destructive"
+                  }`}
+                >
+                  {passkeyMsg}
+                </p>
+              )}
+            </div>
+          </div>
+
+          <div
+            id="passwort"
+            className="bg-card border-border scroll-mt-28 rounded-xl border p-6"
+          >
+            <div className="flex items-center justify-between gap-2">
+              <div className="flex items-center gap-2">
+                <Shield className="text-primary h-5 w-5" />
+                <h2 className="text-lg font-semibold">
+                  {t("settings.passwordReset")}
+                </h2>
+              </div>
+              <Button
+                type="button"
+                variant="outline"
+                onClick={() => setPasswordDialogOpen(true)}
+              >
+                {t("settings.changePassword")}
+              </Button>
+            </div>
+            <p className="text-muted-foreground mt-1 text-xs">
+              {t("settings.changePasswordDescription")}
+            </p>
+          </div>
+
+          <Dialog
+            open={passwordDialogOpen}
+            onOpenChange={(open) => {
+              setPasswordDialogOpen(open);
+              if (!open) {
+                setCurrentPassword("");
+                setNewPassword("");
+                setConfirmPassword("");
+                setPasswordMsg(null);
+                setPasswordMsgType(null);
+              }
+            }}
+          >
+            <DialogContent className="sm:max-w-xl">
+              <DialogHeader>
+                <DialogTitle>{t("settings.passwordReset")}</DialogTitle>
+                <DialogDescription>
+                  {t("settings.changePasswordDescription")}
+                </DialogDescription>
+              </DialogHeader>
+
+              <form onSubmit={handleChangePassword} className="space-y-3">
+                <div className="grid gap-3 sm:grid-cols-3">
+                  <div className="space-y-1.5">
+                    <Label htmlFor="current-password">
+                      {t("settings.currentPassword")}
                     </Label>
-                    <select
-                      id="language-select"
-                      value={locale}
-                      onChange={(e) => setLocale(e.target.value as Locale)}
-                      className="border-input bg-background text-foreground ring-offset-background focus-visible:ring-ring flex h-9 w-full rounded-md border px-3 py-1 text-sm focus-visible:ring-2 focus-visible:ring-offset-2 focus-visible:outline-none"
-                    >
-                      {locales.map((loc) => (
-                        <option key={loc} value={loc}>
-                          {localeLabels[loc as Locale]}
-                        </option>
-                      ))}
-                    </select>
-                    <p className="text-muted-foreground text-xs">
-                      {t("settings.languageDescription")}
-                    </p>
+                    <PasswordInput
+                      id="current-password"
+                      value={currentPassword}
+                      onChange={(e) => setCurrentPassword(e.target.value)}
+                    />
+                  </div>
+                  <div className="space-y-1.5">
+                    <Label htmlFor="new-password">
+                      {t("settings.newPassword")}
+                    </Label>
+                    <PasswordInput
+                      id="new-password"
+                      value={newPassword}
+                      onChange={(e) => setNewPassword(e.target.value)}
+                    />
+                  </div>
+                  <div className="space-y-1.5">
+                    <Label htmlFor="confirm-password">
+                      {t("settings.confirmNewPassword")}
+                    </Label>
+                    <PasswordInput
+                      id="confirm-password"
+                      value={confirmPassword}
+                      onChange={(e) => setConfirmPassword(e.target.value)}
+                    />
                   </div>
                 </div>
 
-                {saveMsg && (
+                {passwordMsg && (
                   <p
                     role="alert"
                     className={`text-sm ${
-                      saveMsgType === "success"
+                      passwordMsgType === "success"
                         ? "text-dracula-green"
                         : "text-destructive"
                     }`}
                   >
-                    {saveMsg}
+                    {passwordMsg}
                   </p>
                 )}
 
-                <div className="flex justify-end">
-                  <Button type="submit" disabled={saving}>
-                    {saving ? (
-                      <Loader2 className="mr-2 h-4 w-4 animate-spin" />
-                    ) : (
-                      <Save className="mr-2 h-4 w-4" />
-                    )}
-                    {t("common.save")}
-                  </Button>
-                </div>
-              </form>
-            </div>
-          </section>
-
-          <section id="section-sicherheit" className="scroll-mt-28 space-y-3">
-            <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">{t("settings.security")}</h2>
-
-            <div
-              id="passkeys"
-              className="bg-card border-border scroll-mt-28 rounded-xl border p-6"
-            >
-              <div className="mb-4 flex items-center gap-2">
-                <Shield className="text-primary h-5 w-5" />
-                <h2 className="text-lg font-semibold">
-                  {t("settings.passkeys")}
-                </h2>
-              </div>
-              <PasskeyListSection isAuthenticated={isAuthenticated} />
-              <div className="mt-4 flex justify-end">
                 <Button
+                  type="submit"
                   variant="outline"
-                  onClick={handleAddPasskey}
-                  disabled={passkeyLoading}
+                  disabled={passwordSaving}
                 >
-                  {passkeyLoading ? (
+                  {passwordSaving ? (
                     <Loader2 className="mr-2 h-4 w-4 animate-spin" />
                   ) : (
-                    <KeyRound className="mr-2 h-4 w-4" />
+                    <Save className="mr-2 h-4 w-4" />
                   )}
-                  {t("settings.addPasskey")}
-                </Button>
-                {passkeyMsg && (
-                  <p
-                    role="alert"
-                    className={`mt-2 text-sm ${
-                      passkeyMsgType === "success"
-                        ? "text-dracula-green"
-                        : "text-destructive"
-                    }`}
-                  >
-                    {passkeyMsg}
-                  </p>
-                )}
-              </div>
-            </div>
-
-            <div id="passwort" className="bg-card border-border scroll-mt-28 rounded-xl border p-6">
-              <div className="flex items-center justify-between gap-2">
-                <div className="flex items-center gap-2">
-                  <Shield className="text-primary h-5 w-5" />
-                  <h2 className="text-lg font-semibold">
-                    {t("settings.passwordReset")}
-                  </h2>
-                </div>
-                <Button
-                  type="button"
-                  variant="outline"
-                  onClick={() => setPasswordDialogOpen(true)}
-                >
                   {t("settings.changePassword")}
                 </Button>
-              </div>
-              <p className="text-muted-foreground mt-1 text-xs">
-                {t("settings.changePasswordDescription")}
-              </p>
-            </div>
-
-            <Dialog
-              open={passwordDialogOpen}
-              onOpenChange={(open) => {
-                setPasswordDialogOpen(open);
-                if (!open) {
-                  setCurrentPassword("");
-                  setNewPassword("");
-                  setConfirmPassword("");
-                  setPasswordMsg(null);
-                  setPasswordMsgType(null);
-                }
-              }}
-            >
-              <DialogContent className="sm:max-w-xl">
-                <DialogHeader>
-                  <DialogTitle>{t("settings.passwordReset")}</DialogTitle>
-                  <DialogDescription>
-                    {t("settings.changePasswordDescription")}
-                  </DialogDescription>
-                </DialogHeader>
-
-                <form onSubmit={handleChangePassword} className="space-y-3">
-                  <div className="grid gap-3 sm:grid-cols-3">
-                    <div className="space-y-1.5">
-                      <Label htmlFor="current-password">
-                        {t("settings.currentPassword")}
-                      </Label>
-                      <PasswordInput
-                        id="current-password"
-                        value={currentPassword}
-                        onChange={(e) => setCurrentPassword(e.target.value)}
-                      />
-                    </div>
-                    <div className="space-y-1.5">
-                      <Label htmlFor="new-password">
-                        {t("settings.newPassword")}
-                      </Label>
-                      <PasswordInput
-                        id="new-password"
-                        value={newPassword}
-                        onChange={(e) => setNewPassword(e.target.value)}
-                      />
-                    </div>
-                    <div className="space-y-1.5">
-                      <Label htmlFor="confirm-password">
-                        {t("settings.confirmNewPassword")}
-                      </Label>
-                      <PasswordInput
-                        id="confirm-password"
-                        value={confirmPassword}
-                        onChange={(e) => setConfirmPassword(e.target.value)}
-                      />
-                    </div>
-                  </div>
-
-                  {passwordMsg && (
-                    <p
-                      role="alert"
-                      className={`text-sm ${
-                        passwordMsgType === "success"
-                          ? "text-dracula-green"
-                          : "text-destructive"
-                      }`}
-                    >
-                      {passwordMsg}
-                    </p>
-                  )}
-
-                  <Button
-                    type="submit"
-                    variant="outline"
-                    disabled={passwordSaving}
-                  >
-                    {passwordSaving ? (
-                      <Loader2 className="mr-2 h-4 w-4 animate-spin" />
-                    ) : (
-                      <Save className="mr-2 h-4 w-4" />
-                    )}
-                    {t("settings.changePassword")}
-                  </Button>
-                </form>
-              </DialogContent>
-            </Dialog>
-
-          </section>
-
-          {hasNotificationServices && (
-            <section
-              id="section-benachrichtigungen"
-              className="scroll-mt-28 space-y-3"
-            >
-              <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
-                {t("settings.categoryNotifications")}
-              </h2>
-              {serviceAvailability.telegramGlobal && (
-                <TelegramSection
-                  id="telegram"
-                  isAuthenticated={isAuthenticated}
-                />
-              )}
-              {serviceAvailability.ntfyGlobal && (
-                <NtfySection id="ntfy" isAuthenticated={isAuthenticated} />
-              )}
-              {serviceAvailability.webPushGlobal && (
-                <WebPushSection id="web-push" />
-              )}
-            </section>
-          )}
+              </form>
+            </DialogContent>
+          </Dialog>
+        </section>
 
+        {hasNotificationServices && (
           <section
-            id="section-personalization"
+            id="section-benachrichtigungen"
             className="scroll-mt-28 space-y-3"
           >
             <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
-              {t("settings.categoryPersonalization")}
+              {t("settings.categoryNotifications")}
             </h2>
-            <DashboardLayoutSection id="dashboard-layout" />
-            <ThresholdsSection id="thresholds" />
+            {serviceAvailability.telegramGlobal && (
+              <TelegramSection
+                id="telegram"
+                isAuthenticated={isAuthenticated}
+              />
+            )}
+            {serviceAvailability.ntfyGlobal && (
+              <NtfySection id="ntfy" isAuthenticated={isAuthenticated} />
+            )}
+            {serviceAvailability.webPushGlobal && (
+              <WebPushSection id="web-push" />
+            )}
           </section>
+        )}
 
-          <section id="section-integration" className="scroll-mt-28 space-y-3">
+        <section
+          id="section-personalization"
+          className="scroll-mt-28 space-y-3"
+        >
+          <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
+            {t("settings.categoryPersonalization")}
+          </h2>
+          <DashboardLayoutSection id="dashboard-layout" />
+          <ThresholdsSection id="thresholds" />
+        </section>
+
+        <section id="section-integration" className="scroll-mt-28 space-y-3">
+          <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
+            {t("settings.categoryIntegration")}
+          </h2>
+          <WithingsSection id="withings" isAuthenticated={isAuthenticated} />
+          {serviceAvailability.moodLogGlobal !== false && (
+            <MoodLogSection t={t} />
+          )}
+          <InsightsSettingsSection
+            id="insights"
+            isAuthenticated={isAuthenticated}
+          />
+        </section>
+
+        {serviceAvailability.apiGlobal && (
+          <section id="section-api" className="scroll-mt-28 space-y-3">
             <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
-              {t("settings.categoryIntegration")}
+              {t("settings.categoryApi")}
             </h2>
-            <WithingsSection id="withings" isAuthenticated={isAuthenticated} />
-            {serviceAvailability.moodLogGlobal !== false && <MoodLogSection t={t} />}
-            <InsightsSettingsSection
-              id="insights"
+            <ApiEndpointsSection id="api-endpoints" />
+            <ApiTokensSection
+              id="api-tokens"
               isAuthenticated={isAuthenticated}
             />
           </section>
+        )}
 
-          {serviceAvailability.apiGlobal && (
-            <section id="section-api" className="scroll-mt-28 space-y-3">
-              <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
-                {t("settings.categoryApi")}
-              </h2>
-              <ApiEndpointsSection id="api-endpoints" />
-              <ApiTokensSection
-                id="api-tokens"
-                isAuthenticated={isAuthenticated}
-              />
-            </section>
-          )}
+        <section id="section-export" className="scroll-mt-28 space-y-3">
+          <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
+            {t("settings.export")}
+          </h2>
+          <ExportSection id="export" />
+        </section>
 
-          <section id="section-export" className="scroll-mt-28 space-y-3">
-            <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">{t("settings.export")}</h2>
-            <ExportSection id="export" />
-          </section>
-
-          <section id="section-danger-zone" className="scroll-mt-28 space-y-3">
-            <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
-              {t("settings.dangerZoneTitle")}
-            </h2>
-            <DataResetSection id="daten" />
-          </section>
-        </div>
+        <section id="section-danger-zone" className="scroll-mt-28 space-y-3">
+          <h2 className="text-muted-foreground text-sm font-semibold tracking-wider uppercase">
+            {t("settings.dangerZoneTitle")}
+          </h2>
+          <DataResetSection id="daten" />
+        </section>
+      </div>
     </div>
   );
 }
@@ -827,7 +831,10 @@ function PasskeyListSection({ isAuthenticated }: { isAuthenticated: boolean }) {
         </table>
       </div>
       {deleteMsg && (
-        <div role="alert" className="text-destructive mt-2 flex items-center gap-2 text-sm">
+        <div
+          role="alert"
+          className="text-destructive mt-2 flex items-center gap-2 text-sm"
+        >
           <AlertTriangle className="h-4 w-4" />
           {deleteMsg}
         </div>
@@ -1326,7 +1333,8 @@ function ApiTokensSection({
           )}
           {latestActiveUse && (
             <Badge variant="outline" className="text-xs">
-              {t("settings.tokenTableLastUsed")}: {formatDateTime(latestActiveUse)}
+              {t("settings.tokenTableLastUsed")}:{" "}
+              {formatDateTime(latestActiveUse)}
             </Badge>
           )}
         </div>
@@ -1368,7 +1376,11 @@ function ApiTokensSection({
           </div>
         )}
 
-        {tokenMsg && <p role="alert" className="text-destructive text-sm">{tokenMsg}</p>}
+        {tokenMsg && (
+          <p role="alert" className="text-destructive text-sm">
+            {tokenMsg}
+          </p>
+        )}
 
         {/* Token table (active) */}
         <div>
@@ -1586,9 +1598,8 @@ function ExportSection({ id }: { id: string }) {
       if (!res.ok) return;
       const json = await res.json();
 
-      const { generateDoctorReportPDF } = await import(
-        "@/lib/doctor-report-pdf"
-      );
+      const { generateDoctorReportPDF } =
+        await import("@/lib/doctor-report-pdf");
       const doc = generateDoctorReportPDF(json.data, { t, locale });
       const fileSlug = locale === "de" ? "gesundheitsbericht" : "health-report";
       doc.save(`${fileSlug}-${new Date().toISOString().slice(0, 10)}.pdf`);
@@ -2445,7 +2456,12 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
       });
       if (res.ok) {
         const json = await res.json();
-        setMsg(t("settings.moodLogSyncResult").replace("{count}", String(json.data.imported)));
+        setMsg(
+          t("settings.moodLogSyncResult").replace(
+            "{count}",
+            String(json.data.imported),
+          ),
+        );
         setMsgType("success");
         await refetchStatus();
       } else {
@@ -2469,19 +2485,29 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
   }
 
   return (
-    <div id="moodlog" className="bg-card border-border scroll-mt-28 rounded-xl border p-6 space-y-4">
+    <div
+      id="moodlog"
+      className="bg-card border-border scroll-mt-28 space-y-4 rounded-xl border p-6"
+    >
       <div className="flex flex-wrap items-start justify-between gap-2">
         <div className="flex items-center gap-2">
           <Smile className="text-primary h-5 w-5" />
           <h2 className="text-lg font-semibold">
-            <a href="https://moodlog.onback.io" target="_blank" rel="noopener noreferrer" className="hover:underline">
+            <a
+              href="https://moodlog.onback.io"
+              target="_blank"
+              rel="noopener noreferrer"
+              className="hover:underline"
+            >
               {t("settings.moodLogTitle")}
             </a>
           </h2>
         </div>
         {status?.configured && (
           <Badge className="border-dracula-green/30 bg-dracula-green/15 text-dracula-green">
-            {status.enabled ? t("settings.withingsConnected") : t("settings.configured")}
+            {status.enabled
+              ? t("settings.withingsConnected")
+              : t("settings.configured")}
           </Badge>
         )}
       </div>
@@ -2512,7 +2538,11 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
             onChange={(e) => setApiKey(e.target.value)}
           />
         </div>
-        <Button type="submit" disabled={saving || (!url.trim() && !apiKey.trim())} size="sm">
+        <Button
+          type="submit"
+          disabled={saving || (!url.trim() && !apiKey.trim())}
+          size="sm"
+        >
           {saving && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
           <Save className="mr-2 h-4 w-4" />
           {t("common.save")}
@@ -2527,7 +2557,11 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
             <div>
               <Label>{t("settings.moodLogWebhookSecret")}</Label>
               <div className="flex gap-2">
-                <Input value={status.webhookSecret} readOnly className="font-mono text-xs" />
+                <Input
+                  value={status.webhookSecret}
+                  readOnly
+                  className="font-mono text-xs"
+                />
                 <Button
                   variant="outline"
                   size="sm"
@@ -2540,7 +2574,7 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
                   {t("common.copied").replace("!", "")}
                 </Button>
               </div>
-              <p className="text-muted-foreground text-xs mt-1">
+              <p className="text-muted-foreground mt-1 text-xs">
                 {t("settings.moodLogWebhookSecretHelp")}
               </p>
             </div>
@@ -2581,7 +2615,9 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
               </AlertDialogTrigger>
               <AlertDialogContent>
                 <AlertDialogHeader>
-                  <AlertDialogTitle>{t("settings.moodLogFullSyncTitle")}</AlertDialogTitle>
+                  <AlertDialogTitle>
+                    {t("settings.moodLogFullSyncTitle")}
+                  </AlertDialogTitle>
                   <AlertDialogDescription>
                     {t("settings.moodLogFullSyncDescription")}
                   </AlertDialogDescription>
@@ -2604,7 +2640,9 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
               </AlertDialogTrigger>
               <AlertDialogContent>
                 <AlertDialogHeader>
-                  <AlertDialogTitle>{t("settings.moodLogDisconnectTitle")}</AlertDialogTitle>
+                  <AlertDialogTitle>
+                    {t("settings.moodLogDisconnectTitle")}
+                  </AlertDialogTitle>
                   <AlertDialogDescription>
                     {t("settings.moodLogDisconnectDescription")}
                   </AlertDialogDescription>
@@ -2623,7 +2661,10 @@ function MoodLogSection({ t }: { t: (key: string) => string }) {
 
       {/* Status message */}
       {msg && (
-        <p role="alert" className={`text-sm ${msgType === "error" ? "text-destructive" : "text-dracula-green"}`}>
+        <p
+          role="alert"
+          className={`text-sm ${msgType === "error" ? "text-destructive" : "text-dracula-green"}`}
+        >
           {msg}
         </p>
       )}
@@ -2694,7 +2735,8 @@ function InsightsSettingsSection({
     }
   }, [queryClient, t]);
 
-  const hasProvider = settings?.codexStatus === "connected" || settings?.hasAdminKey;
+  const hasProvider =
+    settings?.codexStatus === "connected" || settings?.hasAdminKey;
 
   async function handleConnect() {
     window.location.href = "/api/auth/codex/authorize";
@@ -2704,7 +2746,9 @@ function InsightsSettingsSection({
     setDisconnecting(true);
     setMsg(null);
     try {
-      const res = await fetch("/api/auth/codex/disconnect", { method: "DELETE" });
+      const res = await fetch("/api/auth/codex/disconnect", {
+        method: "DELETE",
+      });
       if (!res.ok) {
         const json = await res.json();
         throw new Error(json.error);
@@ -2802,9 +2846,14 @@ function InsightsSettingsSection({
               <div>
                 <p className="text-sm font-medium">ChatGPT verbunden</p>
                 <p className="text-muted-foreground text-xs">
-                  Insights werden über dein ChatGPT-Abo generiert — keine zusätzlichen Kosten.
+                  Insights werden über dein ChatGPT-Abo generiert — keine
+                  zusätzlichen Kosten.
                   {settings.codexConnectedAt && (
-                    <> Verbunden seit {formatDateTime(settings.codexConnectedAt)}.</>
+                    <>
+                      {" "}
+                      Verbunden seit {formatDateTime(settings.codexConnectedAt)}
+                      .
+                    </>
                   )}
                 </p>
               </div>
@@ -2828,17 +2877,23 @@ function InsightsSettingsSection({
               <div>
                 <p className="text-sm font-medium">Mit ChatGPT verbinden</p>
                 <p className="text-muted-foreground text-xs">
-                  Verbinde dein ChatGPT Pro/Max-Konto um KI-gestützte Gesundheitsanalysen basierend auf
-                  aktuellen medizinischen Leitlinien zu erhalten. Keine zusätzlichen API-Kosten.
+                  Verbinde dein ChatGPT Pro/Max-Konto um KI-gestützte
+                  Gesundheitsanalysen basierend auf aktuellen medizinischen
+                  Leitlinien zu erhalten. Keine zusätzlichen API-Kosten.
                 </p>
               </div>
-              <Button variant="outline" onClick={handleConnect} className="w-full sm:w-auto">
+              <Button
+                variant="outline"
+                onClick={handleConnect}
+                className="w-full sm:w-auto"
+              >
                 <Sparkles className="mr-2 h-4 w-4" />
                 Mit ChatGPT verbinden
               </Button>
               {settings?.hasAdminKey && (
                 <p className="text-muted-foreground text-xs">
-                  Alternativ nutzt HealthLog den vom Administrator konfigurierten KI-Anbieter.
+                  Alternativ nutzt HealthLog den vom Administrator
+                  konfigurierten KI-Anbieter.
                 </p>
               )}
             </div>
@@ -2986,7 +3041,20 @@ function UserAIProviderSubsection() {
     setTesting(true);
     setTestMsg(null);
     try {
-      const res = await fetch("/api/ai/test", { method: "POST" });
+      // v1.4: pass the *current* dropdown / input selection so the test
+      // honours unsaved changes. Plaintext keys never persist server-side.
+      const overrideBody: Record<string, string> = {};
+      if (provider) overrideBody.provider = provider;
+      if (model.trim()) overrideBody.model = model.trim();
+      if (baseUrl.trim()) overrideBody.baseUrl = baseUrl.trim();
+      if (anthropicKey.trim()) overrideBody.anthropicKey = anthropicKey.trim();
+      if (localKey.trim()) overrideBody.localKey = localKey.trim();
+      const hasOverride = Object.keys(overrideBody).length > 0;
+      const res = await fetch("/api/ai/test", {
+        method: "POST",
+        headers: hasOverride ? { "Content-Type": "application/json" } : {},
+        body: hasOverride ? JSON.stringify(overrideBody) : undefined,
+      });
       const json = await res.json();
       if (!res.ok) {
         setTestMsg(json.error || `HTTP ${res.status}`);
diff --git a/src/components/ui/__tests__/empty-state.test.tsx b/src/components/ui/__tests__/empty-state.test.tsx
new file mode 100644
index 000000000..1247e09bd
--- /dev/null
+++ b/src/components/ui/__tests__/empty-state.test.tsx
@@ -0,0 +1,49 @@
+import { describe, expect, it } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+import { EmptyState } from "../empty-state";
+
+describe("<EmptyState>", () => {
+  it("renders title, description, and action inside a polite live region", () => {
+    const html = renderToStaticMarkup(
+      <EmptyState
+        title="Noch keine Messungen"
+        description="Lege deine erste Messung an."
+        action={<button type="button">Messung anlegen</button>}
+      />,
+    );
+    expect(html).toContain("Noch keine Messungen");
+    expect(html).toContain("Lege deine erste Messung an.");
+    expect(html).toContain("Messung anlegen");
+    expect(html).toContain('role="status"');
+    expect(html).toContain('aria-live="polite"');
+  });
+
+  it("hides the decorative icon from assistive tech", () => {
+    const html = renderToStaticMarkup(
+      <EmptyState icon={<svg data-testid="icon" />} title="leer" />,
+    );
+    // The icon's wrapper carries aria-hidden so the icon doesn't
+    // double-announce alongside the title.
+    expect(html).toMatch(/aria-hidden="true"[^>]*>[^<]*<svg/);
+  });
+
+  it("compact variant tightens spacing", () => {
+    const def = renderToStaticMarkup(<EmptyState title="default" />);
+    const compact = renderToStaticMarkup(
+      <EmptyState title="compact" size="compact" />,
+    );
+    expect(def).toContain("py-8");
+    expect(compact).toContain("py-4");
+    expect(compact).not.toContain("py-8");
+  });
+
+  it("plain variant drops the dashed wrapper", () => {
+    const card = renderToStaticMarkup(<EmptyState title="x" />);
+    const plain = renderToStaticMarkup(
+      <EmptyState title="x" variant="plain" />,
+    );
+    expect(card).toContain("border-dashed");
+    expect(plain).not.toContain("border-dashed");
+  });
+});
diff --git a/src/components/ui/__tests__/input.test.tsx b/src/components/ui/__tests__/input.test.tsx
new file mode 100644
index 000000000..a5b7197a5
--- /dev/null
+++ b/src/components/ui/__tests__/input.test.tsx
@@ -0,0 +1,31 @@
+import { describe, expect, it } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+import { Input } from "../input";
+
+describe("<Input>", () => {
+  it("defaults autoComplete to off and tells password managers to skip", () => {
+    const html = renderToStaticMarkup(<Input id="weight" />);
+    expect(html).toContain('autoComplete="off"');
+    expect(html).toContain('data-lpignore="true"');
+    expect(html).toContain('data-1p-ignore="true"');
+  });
+
+  it("respects an explicit autoComplete value and drops the ignore attrs", () => {
+    const html = renderToStaticMarkup(
+      <Input id="email" type="email" autoComplete="email" />,
+    );
+    expect(html).toContain('autoComplete="email"');
+    expect(html).not.toContain('data-lpignore="true"');
+    expect(html).not.toContain('data-1p-ignore="true"');
+  });
+
+  it("explicit autoComplete=username keeps password manager active for login flows", () => {
+    const html = renderToStaticMarkup(
+      <Input id="username" autoComplete="username" />,
+    );
+    expect(html).toContain('autoComplete="username"');
+    expect(html).not.toContain("lpignore");
+    expect(html).not.toContain("1p-ignore");
+  });
+});
diff --git a/src/components/ui/__tests__/skeleton.test.tsx b/src/components/ui/__tests__/skeleton.test.tsx
new file mode 100644
index 000000000..4db352ca3
--- /dev/null
+++ b/src/components/ui/__tests__/skeleton.test.tsx
@@ -0,0 +1,24 @@
+import { describe, expect, it } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+import { Skeleton } from "../skeleton";
+
+describe("<Skeleton>", () => {
+  it("renders a presentation node so screen readers skip it", () => {
+    const html = renderToStaticMarkup(<Skeleton className="h-4 w-32" />);
+    expect(html).toContain('role="presentation"');
+    expect(html).toContain('aria-hidden="true"');
+  });
+
+  it("preserves caller classes alongside the pulse animation", () => {
+    const html = renderToStaticMarkup(
+      <Skeleton className="h-8 rounded-full" />,
+    );
+    // The pulse class drives the visual shimmer; honour reduce-motion.
+    expect(html).toContain("animate-pulse");
+    expect(html).toContain("motion-reduce:animate-none");
+    // Caller's classes should survive the merge.
+    expect(html).toContain("h-8");
+    expect(html).toContain("rounded-full");
+  });
+});
diff --git a/src/components/ui/empty-state.tsx b/src/components/ui/empty-state.tsx
new file mode 100644
index 000000000..7e5e1e187
--- /dev/null
+++ b/src/components/ui/empty-state.tsx
@@ -0,0 +1,118 @@
+import * as React from "react";
+
+import { cn } from "@/lib/utils";
+
+/**
+ * Reusable empty-state for lists, tiles, and chart panels that have no
+ * data yet. Always pair an icon, a one-sentence explanation, and a
+ * single primary action. Mounts inside the same container the loaded
+ * UI uses so the layout does not shift on first data.
+ *
+ * Pattern (per `docs/ui-guidelines.md` §4.2):
+ *
+ *   <EmptyState
+ *     icon={<Plus className="size-6" />}
+ *     title={t("empty.measurements.title")}
+ *     description={t("empty.measurements.description")}
+ *     action={<Button>{t("empty.measurements.add")}</Button>}
+ *   />
+ */
+export interface EmptyStateProps extends Omit<
+  React.HTMLAttributes<HTMLDivElement>,
+  "title"
+> {
+  icon?: React.ReactNode;
+  title: React.ReactNode;
+  description?: React.ReactNode;
+  action?: React.ReactNode;
+  /**
+   * `"card"` (default) wraps the empty-state in a bordered surface so
+   * it sits visually inside a list/tile.
+   * `"plain"` renders inline without the wrapper — for use inside
+   * chart panels that already have their own card.
+   */
+  variant?: "card" | "plain";
+  /**
+   * Compact density for use inside tiles or table-row empty rows.
+   */
+  size?: "default" | "compact";
+}
+
+function EmptyState({
+  icon,
+  title,
+  description,
+  action,
+  variant = "card",
+  size = "default",
+  className,
+  ...props
+}: EmptyStateProps) {
+  const inner = (
+    <div
+      className={cn(
+        "flex flex-col items-center justify-center text-center",
+        size === "compact" ? "gap-2 py-4" : "gap-3 py-8",
+      )}
+    >
+      {icon ? (
+        <div
+          aria-hidden="true"
+          className={cn(
+            "text-muted-foreground bg-muted/60 flex items-center justify-center rounded-full",
+            size === "compact" ? "size-8 p-1.5" : "size-12 p-2.5",
+          )}
+        >
+          {icon}
+        </div>
+      ) : null}
+      <div className="space-y-1">
+        <p
+          className={cn(
+            "font-medium",
+            size === "compact" ? "text-sm" : "text-base",
+          )}
+        >
+          {title}
+        </p>
+        {description ? (
+          <p className="text-muted-foreground max-w-xs text-sm">
+            {description}
+          </p>
+        ) : null}
+      </div>
+      {action ? <div className="mt-1">{action}</div> : null}
+    </div>
+  );
+
+  if (variant === "plain") {
+    return (
+      <div
+        data-slot="empty-state"
+        role="status"
+        aria-live="polite"
+        className={cn("w-full", className)}
+        {...props}
+      >
+        {inner}
+      </div>
+    );
+  }
+
+  return (
+    <div
+      data-slot="empty-state"
+      role="status"
+      aria-live="polite"
+      className={cn(
+        "border-border bg-card rounded-lg border border-dashed",
+        className,
+      )}
+      {...props}
+    >
+      {inner}
+    </div>
+  );
+}
+
+export { EmptyState };
diff --git a/src/components/ui/input.tsx b/src/components/ui/input.tsx
index f16c2c0ec..95a3a82bc 100644
--- a/src/components/ui/input.tsx
+++ b/src/components/ui/input.tsx
@@ -2,11 +2,40 @@ import * as React from "react";
 
 import { cn } from "@/lib/utils";
 
-function Input({ className, type, ...props }: React.ComponentProps<"input">) {
+/**
+ * Base input primitive.
+ *
+ * v1.4 hardening: defaults `autoComplete` to `"off"` and tells
+ * LastPass / 1Password to skip the field when the caller does not
+ * opt in to a semantic autocomplete value. HealthLog is a health-data
+ * app — letting browsers / password managers autofill measurement,
+ * medication, mood, and AI-token inputs with the user's last-saved
+ * email or account password is at best confusing and at worst leaks
+ * credentials into a free-text field that gets persisted server-side.
+ *
+ * Auth and profile forms (login, register, change-email) keep working
+ * because they already pass an explicit `autoComplete` value —
+ * `"username"`, `"email"`, `"current-password"`, `"new-password"`. When
+ * `autoComplete` is anything other than `"off"`, the LastPass /
+ * 1Password ignore attrs are dropped so password managers fill the
+ * field normally.
+ */
+function Input({
+  className,
+  type,
+  autoComplete,
+  ...props
+}: React.ComponentProps<"input">) {
+  const resolvedAutoComplete = autoComplete ?? "off";
+  const skipAutofill = resolvedAutoComplete === "off";
+
   return (
     <input
       type={type}
       data-slot="input"
+      autoComplete={resolvedAutoComplete}
+      data-lpignore={skipAutofill ? "true" : undefined}
+      data-1p-ignore={skipAutofill ? "true" : undefined}
       className={cn(
         "file:text-foreground placeholder:text-muted-foreground selection:bg-primary selection:text-primary-foreground dark:bg-input/30 border-input h-9 w-full min-w-0 rounded-md border bg-transparent px-3 py-1 text-base shadow-xs transition-[color,box-shadow] outline-none file:inline-flex file:h-7 file:border-0 file:bg-transparent file:text-sm file:font-medium disabled:pointer-events-none disabled:cursor-not-allowed disabled:opacity-50 md:text-sm",
         "focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px]",
diff --git a/src/components/ui/skeleton.tsx b/src/components/ui/skeleton.tsx
new file mode 100644
index 000000000..b1c980ec0
--- /dev/null
+++ b/src/components/ui/skeleton.tsx
@@ -0,0 +1,32 @@
+import * as React from "react";
+
+import { cn } from "@/lib/utils";
+
+/**
+ * Pulsing placeholder used while data is loading. Wrap text-equivalent
+ * shapes so the page does not jump when real content arrives. Honours
+ * `prefers-reduced-motion` automatically because Tailwind's
+ * `animate-pulse` is disabled by `motion-reduce:animate-none`.
+ *
+ * Pattern: render the same layout the loaded UI will render, with each
+ * dynamic block replaced by a `<Skeleton className="h-X w-Y" />`.
+ */
+function Skeleton({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) {
+  return (
+    <div
+      data-slot="skeleton"
+      role="presentation"
+      aria-hidden="true"
+      className={cn(
+        "bg-muted/60 animate-pulse rounded-md motion-reduce:animate-none",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+export { Skeleton };
diff --git a/src/lib/ai/provider.ts b/src/lib/ai/provider.ts
index 3d3441333..a4282ba50 100644
--- a/src/lib/ai/provider.ts
+++ b/src/lib/ai/provider.ts
@@ -5,14 +5,21 @@ import { CodexClient } from "./codex-client";
 import { OpenAIClient } from "./openai-client";
 import { AnthropicClient } from "./anthropic-client";
 import { LocalOpenAICompatibleClient } from "./local-client";
-import { refreshAccessToken, encryptTokens, decryptTokens } from "./codex-oauth";
+import {
+  refreshAccessToken,
+  encryptTokens,
+  decryptTokens,
+} from "./codex-oauth";
+import { isPublicUrl } from "@/lib/validations/notifications";
 
 const TOKEN_REFRESH_BUFFER_MS = 5 * 60 * 1000; // 5 minutes
 
 class NoProvider implements AIProvider {
   readonly type = "none" as const;
 
-  async generateCompletion(_params: CompletionParams): Promise<CompletionResult> {
+  async generateCompletion(
+    _params: CompletionParams,
+  ): Promise<CompletionResult> {
     throw new Error(
       "No AI provider configured. Connect ChatGPT or set an API key in settings.",
     );
@@ -52,7 +59,9 @@ function buildUserProvider(row: UserAIRow): AIProvider | null {
     case "LOCAL": {
       if (!row.aiBaseUrl) return null;
       return new LocalOpenAICompatibleClient({
-        apiKey: row.aiLocalKeyEncrypted ? decrypt(row.aiLocalKeyEncrypted) : null,
+        apiKey: row.aiLocalKeyEncrypted
+          ? decrypt(row.aiLocalKeyEncrypted)
+          : null,
         model: row.aiModel ?? "local-model",
         baseUrl: row.aiBaseUrl,
       });
@@ -71,7 +80,9 @@ function buildUserProvider(row: UserAIRow): AIProvider | null {
 }
 
 async function resolveAdminProvider(): Promise<AIProvider> {
-  const settings = await prisma.appSettings.findUnique({ where: { id: "singleton" } });
+  const settings = await prisma.appSettings.findUnique({
+    where: { id: "singleton" },
+  });
 
   if (settings?.adminAiKeyEncrypted) {
     return new OpenAIClient({
@@ -84,7 +95,9 @@ async function resolveAdminProvider(): Promise<AIProvider> {
   return new NoProvider();
 }
 
-async function resolveCodexProvider(userId: string): Promise<AIProvider | null> {
+async function resolveCodexProvider(
+  userId: string,
+): Promise<AIProvider | null> {
   const user = await prisma.user.findUnique({
     where: { id: userId },
     select: {
@@ -207,8 +220,7 @@ export async function resolveProvider(userId: string): Promise<AIProvider> {
 
   // 2. Codex OAuth (either explicitly selected or implicit fallback)
   const explicitChoice = userRow?.aiProvider?.toUpperCase();
-  const tryCodex =
-    explicitChoice === "CHATGPT_OAUTH" || !explicitChoice;
+  const tryCodex = explicitChoice === "CHATGPT_OAUTH" || !explicitChoice;
   if (tryCodex) {
     const codex = await resolveCodexProvider(userId);
     if (codex) return codex;
@@ -217,3 +229,120 @@ export async function resolveProvider(userId: string): Promise<AIProvider> {
   // 3. Admin OpenAI key (also acts as fallback for user-OPENAI selection)
   return resolveAdminProvider();
 }
+
+/**
+ * Override that the connection-test endpoint accepts so the user can
+ * verify a provider config they have NOT saved yet (dropdown change → test
+ * before commit). Plaintext keys never persist.
+ */
+export type AITestOverride = {
+  provider?: string | null;
+  model?: string | null;
+  baseUrl?: string | null;
+  anthropicKey?: string | null;
+  localKey?: string | null;
+};
+
+export class AITestConfigError extends Error {
+  readonly status: number;
+  constructor(status: number, message: string) {
+    super(message);
+    this.name = "AITestConfigError";
+    this.status = status;
+  }
+}
+
+/**
+ * Resolve the provider for `/api/ai/test`. Falls back to the persisted user
+ * config when the matching override field is empty, so a user with a stored
+ * Anthropic key can change the model in the dropdown and test it without
+ * re-typing the key. The base URL still goes through the SSRF guard.
+ */
+export async function resolveProviderForTest(
+  userId: string,
+  override: AITestOverride = {},
+): Promise<AIProvider> {
+  const stored = await prisma.user.findUnique({
+    where: { id: userId },
+    select: {
+      aiProvider: true,
+      aiModel: true,
+      aiBaseUrl: true,
+      aiAnthropicKeyEncrypted: true,
+      aiLocalKeyEncrypted: true,
+    },
+  });
+
+  const provider = (override.provider ?? stored?.aiProvider ?? "")
+    .toString()
+    .trim()
+    .toUpperCase();
+  const model = (override.model ?? stored?.aiModel ?? "").toString().trim();
+  const baseUrl = (override.baseUrl ?? stored?.aiBaseUrl ?? "")
+    .toString()
+    .trim();
+
+  // Empty selection: fall back to Codex → admin OpenAI like the regular path.
+  if (!provider) {
+    const codex = await resolveCodexProvider(userId);
+    if (codex) return codex;
+    return resolveAdminProvider();
+  }
+
+  switch (provider) {
+    case "ANTHROPIC": {
+      const apiKey =
+        override.anthropicKey?.trim() ||
+        (stored?.aiAnthropicKeyEncrypted
+          ? decrypt(stored.aiAnthropicKeyEncrypted)
+          : "");
+      if (!apiKey) {
+        throw new AITestConfigError(422, "Anthropic API key not configured");
+      }
+      return new AnthropicClient({
+        apiKey,
+        model: model || "claude-3-5-sonnet-latest",
+        baseUrl: baseUrl || undefined,
+      });
+    }
+    case "LOCAL": {
+      if (!baseUrl) {
+        throw new AITestConfigError(422, "Local provider requires a base URL");
+      }
+      const allowPrivate = process.env.ALLOW_LOCAL_AI_PRIVATE_HOSTS === "true";
+      if (!allowPrivate && !isPublicUrl(baseUrl)) {
+        throw new AITestConfigError(
+          422,
+          "Base URL points to an internal/private host",
+        );
+      }
+      const apiKey =
+        override.localKey?.trim() ||
+        (stored?.aiLocalKeyEncrypted
+          ? decrypt(stored.aiLocalKeyEncrypted)
+          : null);
+      return new LocalOpenAICompatibleClient({
+        apiKey,
+        model: model || "local-model",
+        baseUrl,
+      });
+    }
+    case "CHATGPT_OAUTH": {
+      const codex = await resolveCodexProvider(userId);
+      if (codex) return codex;
+      throw new AITestConfigError(422, "ChatGPT OAuth is not connected");
+    }
+    case "OPENAI": {
+      const admin = await resolveAdminProvider();
+      if (admin.type === "none") {
+        throw new AITestConfigError(
+          422,
+          "Admin OpenAI key is not configured for this instance",
+        );
+      }
+      return admin;
+    }
+    default:
+      throw new AITestConfigError(422, `Unknown provider: ${provider}`);
+  }
+}