feat: compose Android app and verify native calendar and reminders

mobile/test/app/app_controller_test.dart

@@ -9,6 +9,9 @@ import 'package:hepan_everyday/data/json_schedule_import.dart';
 
 import '../support/fakes.dart';
 import '../domain/schedule_engine_test.dart' show course;
+import '../services/calendar_service_test.dart' show CalendarProvider;
+
+import 'package:hepan_everyday/services/android_calendar_service.dart';
 
 void main() {
   setUpAll(tzdata.initializeTimeZones);
@@ -35,6 +38,29 @@ void main() {
     );
   });
   tearDown(() => controller.dispose());
+  test('turning off after interrupted first sync cleans events even without saved IDs', () async {
+    store.value = store.value!.copyWith(
+      courses: [
+        course(id: 'a'),
+        course(id: 'b'),
+      ],
+    );
+    final provider = CalendarProvider()..failAfterFirst = true;
+    final interrupted = AppController(
+      store,
+      notifications,
+      AndroidCalendarService(provider),
+      controller.clock,
+    );
+    await interrupted.initialize();
+    await interrupted.enableCalendarFromUserAction('local');
+    expect(interrupted.calendarSyncError, isNotNull);
+    expect(provider.records, hasLength(1));
+    provider.failAfterFirst = false;
+    await interrupted.disableCalendar(deleteEvents: true);
+    expect(provider.records, isEmpty);
+    interrupted.dispose();
+  });
   test(
     'failed calendar cleanup is retried after reopening while sync is off',
     () async {