feat: Phase 4+5 — admin storage UI, backend proxy, CLAUDE.md enforcement

- backend/app/routers/storage_config.py: 5 admin-only endpoints proxying
  storage-service config + migration API (GET/PATCH/POST/DELETE)
- backend/app/main.py: register storage_config router
- frontend/src/api/client.ts: StorageStatus, MigrationStatus,
  StorageBackendConfig interfaces + 5 API functions
- frontend/src/pages/StorageAdminPage.tsx: full admin UI — backend health
  dot, driver selector (local/S3/WebDAV), conditional credential fields,
  Test & Migrate button, live 2s-poll migration progress bar, Cancel
- frontend/src/App.tsx: /admin/storage route (AdminRoute guard)
- CLAUDE.md: storage enforcement rule, updated Docker tables (6 services,
  3 volumes), §20 in merge checklist
- backend/CLAUDE.md, frontend/CLAUDE.md, doc-service/CLAUDE.md,
  ai-service/CLAUDE.md: updated to reflect storage-service integration
- tests/ALL_TESTS.md + tests/storage-service_tests.md: §20 (20 tests)
- backend/STATUS.md, frontend/STATUS.md: updated with new endpoints/routes
- changelog/2026-04-20_storage-service.md: full change log

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/STATUS.md

@@ -21,6 +21,7 @@ All API calls go through `src/api/client.ts` (single Axios instance, JWT injecte
 | `/admin` | `AdminPage` (redirects to `/admin/users`) | Admin only |
 | `/admin/users` | `AdminUsersPage` | Admin only |
 | `/admin/groups` | `AdminGroupsPage` | Admin only |
+| `/admin/storage` | `StorageAdminPage` | Admin only |
 | `/profile` | `ProfilePage` | Required |
 | `/settings` | `SettingsPage` (placeholder) | Required |
 | `/settings/plugins/:id` | `PluginSettingsPage` | Required (per-plugin access control) |
@@ -114,6 +115,10 @@ Provider selector, per-provider fields, Test Connection, Save.
 
 Upload limits + watch directory config.
 
+### Admin — Storage page (`/admin/storage`)
+
+Current backend status (green/red health dot). Driver selector (local/S3/WebDAV) with conditional credential fields. "Test & Migrate" button triggers an async migration that copies all objects to the new backend, verifies, then switches atomically. Live progress bar with 2s polling (states: validating → migrating → switching → cleaning → done). Cancel button during in-progress migrations.
+
 ### Admin — Users page (`/admin/users`)
 
 User list, toggle active, create user, delete user.
@@ -202,6 +207,7 @@ Key document-related functions:
 - [x] AI suggestion confirm/reject UI (folder + filename)
 - [x] Groups admin UI
 - [x] Replace Axios with native fetch; add global 401 → `/login` redirect for expired sessions
+- [x] Admin storage page with live migration progress bar
 - [ ] Toast notification system
 - [ ] Loading skeletons
 - [ ] Cmd+K global search (`CommandDialog`)