added base homescreen-widget setup, working on Android, iOS in progress

lib/view/login/login.dart

@@ -1,6 +1,9 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
+import '../../background/widget_background_task.dart';
 import '../../state/app/modules/account/bloc/account_bloc.dart';
 import '../../state/app/modules/account/bloc/account_state.dart';
 import '../../theming/light_app_theme.dart';
@@ -34,6 +37,11 @@ class _LoginState extends State<Login> {
 
   void _onLoginSuccess() {
     context.read<AccountBloc>().setStatus(AccountStatus.loggedIn);
+    // Re-register the periodic refresh (cancelAll runs on logout) and kick
+    // off an immediate one-off so the widget populates within seconds
+    // instead of waiting up to 30 minutes for the next periodic slot.
+    unawaited(WidgetBackgroundTask.initialize());
+    unawaited(WidgetBackgroundTask.requestImmediateRefresh());
   }
 
   @override

lib/view/login/login_controller.dart

@@ -7,6 +7,7 @@ import '../../api/errors/error_mapper.dart';
 import '../../api/marianumcloud/talk/room/get_room.dart';
 import '../../api/marianumcloud/talk/room/get_room_params.dart';
 import '../../model/account_data.dart';
+import '../../widget_data/widget_sync.dart';
 
 /// Owns the login flow's transient state (loading, last error) so it can be
 /// driven from a thin Stateful view and unit-tested without a widget tree.
@@ -31,6 +32,11 @@ class LoginController extends ChangeNotifier {
     final user = username.trim().toLowerCase();
     try {
       await AccountData().removeData();
+      // Drop any cached widget snapshot from a previous account before the
+      // new credentials populate it — otherwise a re-login with a different
+      // user briefly shows the previous owner's timetable on the home screen.
+      await WidgetSync.clear();
+      await WidgetSync.triggerUpdate();
       await AccountData().setData(user, password);
       await GetRoom(GetRoomParams(includeStatus: false)).run();
       _loading = false;