calendar and vehicle booking rework

frontend/src/pages/FahrzeugBuchungen.tsx

@@ -48,6 +48,7 @@ import { useNavigate } from 'react-router-dom';
 import { format, parseISO } from 'date-fns';
 import DashboardLayout from '../components/dashboard/DashboardLayout';
 import ChatAwareFab from '../components/shared/ChatAwareFab';
+import ServiceModePage from '../components/shared/ServiceModePage';
 import { useAuth } from '../contexts/AuthContext';
 import { usePermissionContext } from '../contexts/PermissionContext';
 import { useNotification } from '../contexts/NotificationContext';
@@ -93,7 +94,7 @@ function getCategoryLabel(buchungsArt: BuchungsArt, kategorien: BuchungsKategori
 
 function FahrzeugBuchungen() {
   const { user } = useAuth();
-  const { hasPermission } = usePermissionContext();
+  const { hasPermission, isFeatureEnabled } = usePermissionContext();
   const notification = useNotification();
   const navigate = useNavigate();
   const queryClient = useQueryClient();
@@ -230,6 +231,10 @@ function FahrzeugBuchungen() {
   });
 
   // ── Render ─────────────────────────────────────────────────────────────────
+  if (!isFeatureEnabled('fahrzeugbuchungen')) {
+    return <ServiceModePage message="Fahrzeugbuchungen befinden sich aktuell im Wartungsmodus." />;
+  }
+
   return (
     <DashboardLayout>
       <Container maxWidth="xl" sx={{ py: 3 }}>