docs: sync README, AGENTS, CLAUDE, OpenAPI, migration guide for v1.4 (#147)

The v1.4 marathon and the v1.4.1 cycle that followed (per-section
admin extraction, Postgres testcontainers integration suite,
Playwright + axe-core E2E foundation) landed several user- and
operator-facing changes that hadn't been backfilled into the docs
shipped inside the repo. This commit closes that drift.

README.md
  - Adds Multi-tenant ready and Test connection buttons feature
    bullets.
  - Tech-stack model count 25 → 26 (RefreshToken added in v1.4.0).
  - API reference: new "Public + v1.4 additions" section listing
    /api/version, the five Test connection endpoints, the two refresh
    endpoints, and the two new admin endpoints (status-overview,
    backup/test).

AGENTS.md
  - Status block rewritten to reflect what shipped in 1.4.0 vs
    what's in flight for 1.4.1.
  - File layout: settings monolith replaced by /settings/[section]
    routing, admin/page.tsx now the 77-LOC shell, src/components/
    settings/ and src/components/admin/ added.
  - Removed the stale "Settings Page" gotcha (about non-blocking
    set-state-in-effect lint); the rule is strict now.
  - Database Models 25 → 26.

CLAUDE.md
  - Same model-count and component-folder updates as AGENTS.md.
  - Adds Multi-tenant prep and Native API client patterns under
    Important Patterns (HEALTHLOG_PROCESS_TYPE, ENCRYPTION_KEYS,
    BACKUP_S3_*, refresh-token rotation).
  - Lists tests/integration/ and e2e/ in File Layout.

docs/api/openapi.yaml
  - Adds 11 new endpoints: GET /api/version, the five test endpoints
    (Withings, moodLog, Web Push, Glitchtip, Umami), the two refresh
    endpoints, GET /api/admin/status-overview, POST /api/admin/backup/test.
  - The bulk of the diff is prettier reformatting that the existing
    file had drifted from (single → double quotes throughout YAML);
    no semantic change.

docs/migration/v1.3-to-v1.4.md
  - Corrects the now-wrong claim that v1.4 ships no migrations
    (it ships 0025_refresh_tokens + 0025_user_locale_drift_fix).
  - Adds full env-var sections for the Worker/Web split, Encryption
    key versioning, and Off-host backup target.
  - Documents URL changes (/settings#anchor → /settings/[section]).
  - Replaces the "deferred to a future release" list with a
    landed-in-v1.4 vs landed-in-v1.4.1 status table.

docs/migration/v1.3-to-v1.4.md

@@ -1,11 +1,11 @@
 # Migrating from HealthLog 1.3 to 1.4
 
-Both 1.3.x and 1.4.0 use Prisma migrations 0001–0024 and the same
-PostgreSQL schema. The upgrade is **drop-in for self-hosters running
-the GHCR image** — no manual migration step beyond the standard
-`docker compose pull && docker compose up -d`. This guide documents
-what changes for operators and integrators, in case you're extending
-the API.
+v1.4.0 is **drop-in for self-hosters running the GHCR image** — the
+two new migrations (`0025_refresh_tokens`, `0025_user_locale_drift_fix`)
+both apply on container start via `prisma migrate deploy`, and every
+new env var in §Environment variables below has a safe default. This
+guide documents what changes for operators and integrators, in case
+you're extending the API or scaling the deployment.
 
 ## TL;DR
 
@@ -14,25 +14,83 @@ docker compose pull
 docker compose up -d
 ```
 
-That's it. No DB migration to apply, no env vars to add, no breaking
-API change.
+That's it. The migrations are forward-compatible (`IF NOT EXISTS`
+guards), no env vars are _required_ to be added, and no API contract
+changes shape or status code.
 
 ## Database
 
-- Prisma schema unchanged from 1.3.3. Migrations 0001–0024 remain
-  authoritative. v1.4.0 brings no new migration files.
+- **`0025_refresh_tokens`** _(new)_ — adds the `refresh_tokens` table
+  for the native-client 24h access-token / refresh-token rotation
+  flow. Browser cookie sessions don't use it.
+- **`0025_user_locale_drift_fix`** _(new)_ — `ADD COLUMN IF NOT
+EXISTS users.locale TEXT` to backfill an environment that was kept
+  in sync via `prisma db push` rather than `migrate deploy`. No-op
+  on installations that were already current.
+- Both migrations are idempotent. A rollback to 1.3.3 keeps the
+  schema usable; the dropped tables/columns are simply unused.
 
 ## Environment variables
 
-- **`NEXT_PUBLIC_APP_BUILD_SHA`** *(optional, new)* — the short Git
-  SHA of the build, surfaced through `/api/version` so the future
-  About surface can render it. The `docker-publish` workflow can wire
-  this once the About UI lands.
-- **`NEXT_PUBLIC_APP_BUILT_AT`** *(optional, new)* — ISO-8601 build
-  timestamp, same plumbing.
+### About surface
 
-Neither is required. Local `pnpm dev` returns `null` for both fields
-and the UI falls back to "development" wording.
+- **`NEXT_PUBLIC_APP_BUILD_SHA`** _(optional, new)_ — short Git SHA
+  exposed through `/api/version`, rendered on Settings → About.
+- **`NEXT_PUBLIC_APP_BUILT_AT`** _(optional, new)_ — ISO-8601 build
+  timestamp.
+
+Both are optional; without them, the About surface renders
+"development" wording.
+
+### Worker / web split
+
+- **`HEALTHLOG_PROCESS_TYPE`** _(optional, default `all`)_ — set to
+  `web` to disable the pg-boss worker (jobs queue but don't run), or
+  `worker` to refuse all HTTP traffic with `503 + X-HealthLog-Process-Type:
+worker`. Default `all` keeps the single-container behaviour.
+  Only relevant if you're scaling HTTP and the worker independently.
+
+### Encryption-key versioning
+
+- **`ENCRYPTION_KEYS`** _(optional, new)_ — JSON object mapping
+  versioned key IDs to 64-char hex keys, e.g. `{"v1": "...", "v2":
+"..."}`. When present, ciphertexts are written with the
+  `<keyId>.<base64>` format and decrypted by looking up the key ID.
+  Existing 1.3-format ciphertexts (no key prefix) keep decrypting
+  with `ENCRYPTION_KEY` indefinitely.
+- **`ENCRYPTION_ACTIVE_KEY_ID`** _(optional, new)_ — the key ID used
+  for new writes. Must be a key in `ENCRYPTION_KEYS`. Defaults to
+  the legacy single-key behaviour if either is unset.
+- **`ENCRYPTION_KEY`** _(unchanged)_ — still honoured as a fallback
+  when `ENCRYPTION_KEYS` is empty. No action needed for existing
+  installs.
+- Rotation: `pnpm tsx scripts/rotate-encryption-key.ts <newKeyId>`
+  re-encrypts every ciphertext under the new key without downtime.
+  Walk-through in `docs/ops/encryption-key-rotation.md`.
+
+### Off-host backup target _(optional)_
+
+If unset, the existing local `DataBackup` storage continues to work.
+
+- **`BACKUP_S3_ENDPOINT`** — S3-compatible endpoint URL. Leave blank
+  to disable off-host backup.
+- **`BACKUP_S3_BUCKET`** — destination bucket name.
+- **`BACKUP_S3_ACCESS_KEY`**, **`BACKUP_S3_SECRET_KEY`** — IAM
+  credentials. Worker only requests `PutObject` + `GetObject` —
+  never `DeleteObject`. Retention is the bucket's lifecycle policy.
+- **`BACKUP_S3_REGION`** _(default `auto`)_.
+- **`BACKUP_RETENTION_DAYS`** _(default `30`)_ — surfaced in the
+  admin UI; the lifecycle rule on your bucket is the actual enforcer.
+- **`BACKUP_ENCRYPTION_KEY`** — separate 64-char hex key for the
+  AES-GCM envelope of each upload. **Keep offline / in a vault.**
+  Lose this and the off-host backups are unreadable.
+
+### API token hashing _(unchanged but worth re-confirming)_
+
+- **`API_TOKEN_HMAC_KEY`** — 64-char hex string. Used to HMAC
+  Bearer tokens before storage so a DB leak can't be reversed via
+  rainbow table. Same key now also keys the new `RefreshToken` row
+  hashes. **Do not rotate without invalidating every native client.**
 
 ## API
 
@@ -41,6 +99,30 @@ and the UI falls back to "development" wording.
 - **`GET /api/version`** — public, static, returns
   `{ version, buildSha, builtAt, license, repository, changelog, docs }`.
   No authentication.
+- **`POST /api/integrations/withings/test`** — admin-only probe
+  against the saved Withings OAuth connection. Returns `{ ok, latency_ms }`
+  on success.
+- **`POST /api/integrations/moodlog/test`** — admin-only HEAD
+  request against `https://moodlog.app/api/health`. SSRF-guarded.
+- **`POST /api/notifications/web-push/test`** — sends a smoke push
+  notification to the current user's subscribed devices.
+- **`POST /api/monitoring/glitchtip/test`** — fires a benign event
+  at the configured DSN.
+- **`POST /api/monitoring/umami/test`** — verifies the script URL +
+  website ID resolve and respond with the expected payload.
+- **`POST /api/admin/backup/test`** — admin-only round-trip against
+  the configured `BACKUP_S3_*` credentials.
+- **`GET /api/admin/status-overview`** — admin-only aggregator
+  returning the six-card summary the new admin top strip renders in
+  one batched query.
+- **`POST /api/auth/refresh`** — native-client refresh-token
+  rotation. Cookie-session browsers don't use this.
+- **`POST /api/auth/refresh/revoke`** — paired logout-on-device that
+  flips both the refresh row and the matching `ApiToken` row to
+  revoked.
+
+All new admin endpoints are hidden from anonymous traffic by the
+proxy and rate-limited.
 
 ### Behaviour-only changes
 
@@ -111,21 +193,27 @@ n8n, and Health Connect integrations need no change.
   8 000–15 000 in the effective-range resolver) now use the same
   band, anchored on Saint-Maurice et al., JAMA 2020.
 
-## What's deferred to a future release
+## URL changes
 
-The v1.3.3 ecosystem audit identified four architectural rewrites that
-are intentionally outside v1.4.0:
+- **Settings has moved to per-section routes.** `/settings#integrations`
+  → `/settings/integrations`, etc. The legacy `/settings#anchor` URLs
+  still 308-redirect to the new routes; sidebar deep-links and the
+  `<a href="/settings#thresholds">` patterns from 1.3 keep working.
 
-- Settings page split into per-section routes (`/settings/[section]`).
-- Admin page redesign with status-first card grid.
-- AI insights rework with severity-coloured key-findings hero and
-  dynamic chart inclusion via an allowlist token map.
-- Multi-tenant prep (off-host backups, encryption-key versioning,
-  worker/web container split, native-Bearer User-Agent gating).
-- Postgres-backed integration test suite (Testcontainers).
+## What landed in v1.4 vs v1.4.1
 
-These ride a future release; the v1.4 marathon closed every CRIT and
-HIGH the audit identified except those four.
+The v1.3.3 ecosystem audit identified architectural rewrites tracked
+through v1.4. Status as of the v1.4.1 cycle:
+
+| Bucket                                                                                 | Status              |
+| -------------------------------------------------------------------------------------- | ------------------- |
+| Settings page split into `/settings/[section]`                                         | ✓ shipped in v1.4.0 |
+| Admin status-first card grid + aggregator endpoint                                     | ✓ shipped in v1.4.0 |
+| AI insights rework — severity hero + allowlisted inline charts                         | ✓ shipped in v1.4.0 |
+| Multi-tenant prep (off-host backups, key versioning, worker/web split, refresh tokens) | ✓ shipped in v1.4.0 |
+| Per-section admin component extraction (inner monolith → one file per panel)           | ✓ shipped in v1.4.1 |
+| Postgres-backed integration test suite (testcontainers)                                | ✓ shipped in v1.4.1 |
+| Playwright + axe-core E2E foundation                                                   | ✓ shipped in v1.4.1 |
 
 ## Rollback