featur add fahrmeister

frontend/src/hooks/usePermissions.ts

@@ -0,0 +1,12 @@
+import { useAuth } from '../contexts/AuthContext';
+
+export function usePermissions() {
+  const { user } = useAuth();
+  const groups = user?.groups ?? [];
+
+  return {
+    isAdmin:         groups.includes('dashboard_admin'),
+    canChangeStatus: groups.includes('dashboard_admin') || groups.includes('dashboard_fahrmeister'),
+    groups,
+  };
+}