T07b: frontend feature pages — companies + contacts + settings + audit + dashboard + search

- 11 new feature pages (CompaniesList/Detail/Form, ContactsList/Detail/Form,
  SettingsProfile/Roles/Users, AuditLog, GlobalSearchResults)
- 3 page updates (Dashboard with StatCard+ActivityFeed, Settings with tree nav+Outlet,
  TopBar with SearchDropdown)
- 13 new routes in routes/index.tsx
- i18n updates (de.json + en.json) with companies/contacts/settings/audit/search keys
- 12 new test files + 2 existing test fixes (TopBar, AppShell)
- 7 shared components (DataGrid, Tabs, SearchDropdown, CsvImportDialog, StatCard,
  ActivityFeed, UnsavedChangesGuard)
- 16 new API hooks in hooks.ts
- Verification: 141 tests pass, build succeeds, tsc --noEmit clean

.a0/project_state.json

@@ -0,0 +1,16 @@
+{
+  "project_name": "leocrm",
+  "phase": "phase-3-implementation",
+  "status": "T07a_complete_111_tests_build_pass_pushed_22976ab",
+  "last_commit": "22976ab",
+  "completed_tasks": [
+    "T01",
+    "T02",
+    "T03",
+    "T09",
+    "T07a"
+  ],
+  "current_task": null,
+  "next_task": "T07b",
+  "updated_at": "2026-06-29T08:04:01+02:00"
+}