Phase 0 Complete: Tasks 0.7-0.20

- 0.7: UI-Design-Richtlinien (docs/ui-design-guidelines.md, 535 lines)
- 0.8: Theme-Customization Backend (4 theme fields, migration 0023)
- 0.9: Theme-Customization Frontend (SettingsTheme.tsx, themeStore.ts, live preview)
- 0.10: RBAC-Audit (4 plugins secured, 53 routes with require_permission)
- 0.11: LiteLLM-Cleanup (llm_client.py migrated from httpx to litellm)
- 0.12: KI-Agent-Framework docs (plugin-development-guide.md, agent_capabilities field)
- 0.13: Heartbeat configurable (ProactiveSettings, migration 0024, frontend UI)
- 0.14: Unified Search Field-Level RBAC (resolve_permissions + filter_fields_by_permission)
- 0.15: Undo/History-System (EntityHistory model, service, routes, migration 0025, HistoryViewer)
- 0.16: Storage Backend (LocalStorage + S3Storage, DMS/attachments/mail updated)
- 0.17: Import/Export unified Contact fields (firstname, surname, email_1, phone_1)
- 0.18: .gitignore & Config-Cleanup (webui→frontend, python-jose removed, .env untracked)
- 0.19: Mail-Salt Security-Fix (per-account random salt, migration 0026)
- 0.20: AGPL replaced (PyMuPDF→pypdf, OnlyOffice→Collabora, LICENSE + THIRD_PARTY_LICENSES.md)

frontend/src/App.tsx

@@ -3,6 +3,7 @@ import { QueryClient, QueryClientProvider } from '@tanstack/react-query';
 import { AppRouter } from '@/routes';
 import { setUnauthorizedHandler } from '@/api/client';
 import { useAuthStore } from '@/store/authStore';
+import { useThemeStore } from '@/store/themeStore';
 
 const queryClient = new QueryClient({
   defaultOptions: {
@@ -16,6 +17,7 @@ const queryClient = new QueryClient({
 
 export default function App() {
   const { logout } = useAuthStore();
+  const loadThemeFromStorage = useThemeStore((s) => s.loadFromStorage);
 
   React.useEffect(() => {
     setUnauthorizedHandler(() => {
@@ -24,6 +26,11 @@ export default function App() {
     });
   }, [logout]);
 
+  // Load theme from localStorage on app start
+  React.useEffect(() => {
+    loadThemeFromStorage();
+  }, [loadThemeFromStorage]);
+
   return (
     <QueryClientProvider client={queryClient}>
       <AppRouter />