Fix release notification resource and add multiple advance reminders

mobile/test/services/notification_service_test.dart

@@ -4,6 +4,7 @@ import 'package:hepan_everyday/services/local_notification_service.dart';
 import 'package:hepan_everyday/services/notification_service.dart';
 import 'package:hepan_everyday/domain/schedule_engine.dart';
 import 'package:hepan_everyday/domain/app_settings.dart';
+import 'package:hepan_everyday/domain/app_snapshot.dart';
 
 import '../domain/schedule_engine_test.dart' show course;
 
@@ -40,6 +41,78 @@ void main() {
     gateway = AlarmGateway();
     service = LocalNotificationService(gateway);
   });
+  AppSettings multiple(List<int> minutes) {
+    final json = AppSnapshot(settings: settings).toJson();
+    (json['settings'] as Map<String, dynamic>)['reminderOffsets'] = minutes;
+    return AppSnapshot.fromJson(json).settings;
+  }
+
+  test(
+    'selected advance times produce independent alarms and survive refresh',
+    () async {
+      final events = ScheduleEngine.occurrences([course(last: 2)], term);
+      await service.reconcile(
+        events,
+        multiple([5, 15]),
+        DateTime.utc(2026, 9, 9),
+      );
+      expect(gateway.alarms, hasLength(2));
+      expect(gateway.alarms.values.map((a) => a.fireAt.toUtc()).toSet(), {
+        DateTime.utc(2026, 9, 9, 0, 15),
+        DateTime.utc(2026, 9, 9, 0, 25),
+      });
+      final ids = gateway.alarms.keys.toSet();
+      await service.reconcile(
+        events,
+        multiple([15, 5]),
+        DateTime.utc(2026, 9, 9),
+      );
+      expect(gateway.alarms.keys.toSet(), ids);
+      await service.reconcile(events, multiple([5]), DateTime.utc(2026, 9, 9));
+      expect(gateway.alarms, hasLength(1));
+      expect(
+        gateway.alarms.values.single.fireAt.toUtc(),
+        DateTime.utc(2026, 9, 9, 0, 25),
+      );
+    },
+  );
+  test(
+    'elapsed earlier reminder does not remove the later selected reminder',
+    () async {
+      final events = ScheduleEngine.occurrences([course()], term);
+      await service.reconcile(
+        events,
+        multiple([5, 15]),
+        DateTime.utc(2026, 9, 9, 0, 20),
+      );
+      expect(gateway.alarms, hasLength(1));
+      expect(
+        gateway.alarms.values.single.fireAt.toUtc(),
+        DateTime.utc(2026, 9, 9, 0, 25),
+      );
+    },
+  );
+  test(
+    'limit selects earliest reminder instants across all selected times',
+    () async {
+      final events = ScheduleEngine.occurrences(
+        List.generate(501, (i) => course(id: 'c-$i')),
+        term,
+      );
+      final result = await service.reconcile(
+        events,
+        multiple([5, 15]),
+        DateTime.utc(2026, 9, 9),
+      );
+      expect(result.scheduledCount, 400);
+      expect(
+        gateway.alarms.values.every(
+          (a) => a.fireAt.isAtSameMomentAs(DateTime.utc(2026, 9, 9, 0, 15)),
+        ),
+        isTrue,
+      );
+    },
+  );
   test(
     'continuous course schedules one alarm fifteen minutes before school start',
     () async {