simplified code across the app and consolidated duplicated helpers

lib/background/widget_background_task.dart

@@ -17,7 +17,6 @@ import '../api/marianumconnect/queries/timetable_get_timegrid/timetable_get_time
 import '../api/marianumconnect/queries/timetable_get_timegrid/timetable_get_timegrid_response.dart';
 import '../api/marianumconnect/queries/timetable_get_week/timetable_get_week.dart';
 import '../api/mhsl/custom_timetable_event/get/get_custom_timetable_event_response.dart';
-import '../session/session.dart';
 import '../session/session_manager.dart';
 import '../widget_data/widget_data_mapper.dart';
 import '../widget_data/widget_publisher.dart';
@@ -81,16 +80,12 @@ class WidgetBackgroundTask {
   /// Throws on fetch failure so the worker path can signal a retry.
   static Future<void> runRefreshNow({bool force = false}) async {
     await WidgetSync.ensureInitialized();
-    Session? session;
-    try {
-      // Bounded: a hanging keystore read must not stall the caller's budget
-      // (FCM handler ~25s on iOS) forever.
-      session = await SessionManager().waitForLoad().timeout(
-        const Duration(seconds: 10),
-      );
-    } on TimeoutException {
-      session = null;
-    }
+    // Bounded: a hanging keystore read must not stall the caller's budget
+    // (FCM handler ~25s on iOS) forever.
+    final session = await SessionManager().waitForLoad().timeout(
+      const Duration(seconds: 10),
+      onTimeout: () => null,
+    );
     if (session == null) {
       // Deliberately does NOT flip the widget to logged-out: a failed or slow
       // keychain read (locked iOS device during the 06:00 silent push) is
@@ -143,7 +138,6 @@ void _callbackDispatcher() {
 }
 
 Future<void> _refresh() async {
-  await WidgetSync.ensureInitialized();
   // The background isolate doesn't go through main.dart's BlocBuilder, so we
   // re-apply the endpoint the foreground last persisted. Without this the
   // dio singleton would fall back to its hardcoded live default even when
@@ -191,26 +185,13 @@ Future<void> _refresh() async {
   final timegrid = await timegridFuture;
   final customEvents = await customEventsFuture;
 
-  final lessons = timetable.entries;
-
   final [connectDouble, isTeacher] = await Future.wait([
     WidgetSync.getConnectDoubleLessons(),
     WidgetSync.getIsTeacher(),
   ]);
-  final dayData = WidgetDataMapper.buildDayData(
+  final (day: dayData, week: weekData) = WidgetDataMapper.buildSnapshot(
     now: now,
-    lessons: lessons,
-    subjects: subjects,
-    rooms: rooms,
-    holidays: holidays,
-    timegrid: timegrid,
-    customEvents: customEvents,
-    connectDoubleLessons: connectDouble,
-    showClassInsteadOfTeacher: isTeacher,
-  );
-  final weekData = WidgetDataMapper.buildWeekData(
-    now: now,
-    lessons: lessons,
+    lessons: timetable.entries,
     subjects: subjects,
     rooms: rooms,
     holidays: holidays,
@@ -220,10 +201,7 @@ Future<void> _refresh() async {
     showClassInsteadOfTeacher: isTeacher,
   );
 
-  await WidgetSync.writeDayData(dayData);
-  await WidgetSync.writeWeekData(weekData);
-  await WidgetSync.setLoggedIn(true);
-  await WidgetSync.triggerUpdate();
+  await WidgetSync.publishSnapshot(day: dayData, week: weekData);
   log(
     '[widget-bg] refreshed: day=${dayData.lessons.length} '
     'week=${weekData.lessons.length}',