fix: align Android schedule notifications with ADR-0008

[jjoonleo]

Summary

• make Android schedule delivery notification-first by gating native/full-screen alarm paths behind an explicit release-policy flag
• route Android scheduling through schedule notification payload/copy/channel/category defaults
• keep retained native alarm behavior explicit for approved providers such as iOS AlarmKit and future Android policy approval

Closes #529

Tests

• dart format lib/core/services/notification_routing.dart lib/core/services/notification_service.dart lib/domain/entities/alarm_entities.dart lib/domain/use-cases/reconcile_alarms_use_case.dart lib/presentation/app/cubit/alarm_gate_cubit.dart lib/presentation/my_page/my_page_screen.dart test/core/services/notification_routing_test.dart test/core/services/notification_service_test.dart test/data/models/alarm_models_test.dart test/domain/use-cases/reconcile_alarms_use_case_test.dart test/presentation/alarm_allow/alarm_allow_screen_test.dart test/presentation/app/cubit/alarm_gate_cubit_test.dart test/presentation/my_page/my_page_screen_test.dart
• flutter test test/domain/use-cases/reconcile_alarms_use_case_test.dart test/presentation/my_page/my_page_screen_test.dart test/data/models/alarm_models_test.dart test/core/services/notification_routing_test.dart test/core/services/notification_service_test.dart test/presentation/app/cubit/alarm_gate_cubit_test.dart test/presentation/alarm_allow/alarm_allow_screen_test.dart
• flutter analyze