migrated custom timetable events to Marianum-Connect and refactored push notification handling

lib/view/pages/timetable/data/timetable_appointment_factory.dart

@@ -1,5 +1,6 @@
 import 'package:syncfusion_flutter_calendar/calendar.dart';
 
+import '../../../../api/marianumconnect/models/mc_holiday.dart';
 import '../../../../api/marianumconnect/queries/timetable_get_subjects/timetable_get_subjects_response.dart';
 import '../../../../api/marianumconnect/queries/timetable_get_week/timetable_get_week_response.dart';
 import '../../../../api/mhsl/custom_timetable_event/custom_timetable_event.dart';
@@ -16,6 +17,7 @@ class TimetableAppointmentFactory {
   final List<McTimetableEntry> lessons;
   final List<CustomTimetableEvent> customEvents;
   final List<McSubject> subjects;
+  final List<McHoliday> holidays;
   final TimetableSettings settings;
   final DateTime now;
 
@@ -25,6 +27,7 @@ class TimetableAppointmentFactory {
     required this.subjects,
     required this.settings,
     required this.now,
+    this.holidays = const [],
   });
 
   List<Appointment> build() {
@@ -98,6 +101,14 @@ class TimetableAppointmentFactory {
           ),
         )
         .toList();
+    // Ferien ausblenden ist nur für Serien sinnvoll; Syncfusion matcht
+    // Ausnahmen über recurrenceExceptionDates. Überzählige Ferientage, an denen
+    // gar keine Occurrence liegt, ignoriert es folgenlos — daher genügt es, für
+    // jeden Ferientag ein Ausnahmedatum zur Terminzeit einzustreuen, ohne die
+    // RRULE selbst expandieren zu müssen.
+    if (event.skipHolidays && parsed.rule.isNotEmpty) {
+      exceptionDates.addAll(_holidayExceptionDates(event));
+    }
     return Appointment(
       id: CustomAppointment(event),
       startTime: event.startDate,
@@ -128,6 +139,36 @@ class TimetableAppointmentFactory {
     );
   }
 
+  List<DateTime> _holidayExceptionDates(CustomTimetableEvent event) {
+    final result = <DateTime>[];
+    for (final holiday in holidays) {
+      var day = DateTime(
+        holiday.startDate.year,
+        holiday.startDate.month,
+        holiday.startDate.day,
+      );
+      final last = DateTime(
+        holiday.endDate.year,
+        holiday.endDate.month,
+        holiday.endDate.day,
+      );
+      while (!day.isAfter(last)) {
+        result.add(
+          DateTime(
+            day.year,
+            day.month,
+            day.day,
+            event.startDate.hour,
+            event.startDate.minute,
+            event.startDate.second,
+          ),
+        );
+        day = DateTime(day.year, day.month, day.day + 1);
+      }
+    }
+    return result;
+  }
+
   /// All-day convention: a `CustomTimetableEvent` is treated as all-day when
   /// its `startDate` and `endDate` both land on midnight of the same day.
   /// Keeps the backend schema unchanged — the editor stores all-day events as