T08a: Frontend DMS + Tags + Permissions UI — 33 tests, tsc clean, vite build pass

- DMS file browser: folder tree + file grid + upload dropzone + search + preview modal
- DMS share dialog: user/group share + public share links with password+expiry
- DMS bulk actions: bulk move + bulk delete with confirm dialogs
- DMS trash view: deleted files list with restore button
- Tags: TagPicker on company/contact detail pages (new tabs tab)
- Tags: TagCloud + BulkTagDialog for bulk tag assignment
- Permissions: share link creation, permission display, copy-link button
- API clients: dms.ts, tags.ts, permissions.ts
- Routes: /dms, /dms/trash added to router
- Sidebar: DMS nav link updated
- i18n: de.json + en.json translations for DMS/Tags/Permissions
- 33 new tests (5 test files), full regression 276/276 pass
- tsc --noEmit: 0 errors, vite build: 252 modules

frontend/src/routes/index.tsx

@@ -20,6 +20,8 @@ import { SettingsRolesPage } from '@/pages/SettingsRoles';
 import { SettingsUsersPage } from '@/pages/SettingsUsers';
 import { CalendarPage } from '@/pages/Calendar';
 import { CalendarKanbanPage } from '@/pages/CalendarKanban';
+import { DmsPage } from '@/pages/Dms';
+import { DmsTrashPage } from '@/pages/DmsTrash';
 
 const router = createBrowserRouter([
   {
@@ -55,6 +57,8 @@ const router = createBrowserRouter([
       { path: '/search', element: <GlobalSearchResultsPage /> },
       { path: '/calendar', element: <CalendarPage /> },
       { path: '/calendar/kanban', element: <CalendarKanbanPage /> },
+      { path: '/dms', element: <DmsPage /> },
+      { path: '/dms/trash', element: <DmsTrashPage /> },
       {
         path: '/settings',
         element: <SettingsPage />,