added guardian login with views for their assigned childs

lib/api/demo/data/demo_capabilities.dart

@@ -1,5 +1,7 @@
 import '../../../state/app/modules/capabilities/bloc/capabilities_state.dart';
 import '../../../state/app/modules/nextcloud_capabilities/bloc/nextcloud_capabilities_state.dart';
+import '../../marianumconnect/queries/get_capabilities/guardian_child.dart';
+import '../demo_persona.dart';
 
 /// Demo fixtures for the mobile capability flags — everything granted so the
 /// demo persona sees every feature (incl. push) as available and the timetable
@@ -17,6 +19,27 @@ class DemoCapabilities {
     userType: 'STUDENT',
     loaded: true,
   );
+
+  /// Guardian persona with two children, so the child switcher is visible.
+  static CapabilitiesState guardianState() => const CapabilitiesState(
+    pushNotifications: true,
+    userType: 'PARENT',
+    children: [
+      GuardianChild(
+        id: 'demo-child-1',
+        firstName: DemoPersona.studentFirstName,
+        lastName: 'Hoffmann',
+        className: DemoPersona.className,
+      ),
+      GuardianChild(
+        id: 'demo-child-2',
+        firstName: 'Jonas',
+        lastName: 'Hoffmann',
+        className: '6a',
+      ),
+    ],
+    loaded: true,
+  );
 }
 
 /// Demo fixtures for the Nextcloud `files_sharing` capabilities — a permissive