Wire reminder scheduler interface into local repository

lib/features/reminders/scheduling/reminder_scheduler.dart

@@ -0,0 +1,21 @@
+import 'package:relationship_saver/features/local/local_models.dart';
+
+/// Schedules and reconciles reminder deliveries for current local state.
+abstract class ReminderScheduler {
+  /// Reconciles platform schedules to match current enabled reminders.
+  Future<void> reconcile(List<ReminderRule> reminders);
+
+  /// Clears all platform-scheduled reminder jobs.
+  Future<void> clearAll();
+}
+
+/// Default scheduler used until platform notifications are integrated.
+class NoopReminderScheduler implements ReminderScheduler {
+  const NoopReminderScheduler();
+
+  @override
+  Future<void> clearAll() async {}
+
+  @override
+  Future<void> reconcile(List<ReminderRule> reminders) async {}
+}