migrated timetable integration from WebUntis to the MarianumConnect API, implementing a Dio-based client with bearer token authentication, background session validation, and auto-refresh logic.

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

@@ -282,7 +282,7 @@ class LaidOutOverflow extends LaidOutCell {
 int _appointmentPriority(Appointment a) {
   final id = a.id;
   if (id is CustomAppointment) return 0;
-  if (id is WebuntisAppointment && id.lesson.code == 'cancelled') return 1;
+  if (id is LessonAppointment && id.entry.status == 'CANCELLED') return 1;
   return 2;
 }