Mark off items that are already implemented in the current codebase:
Phase 1 (Foundation):
- Status Matrix Module: Modular architecture already implemented
- Exact-Alarm Gate: DailyNotificationExactAlarmManager exists
- BootReceiver Idempotent: DailyNotificationRebootRecoveryManager exists
Phase 2 (Testing & Reliability):
- Error handling improvements: DailyNotificationErrorHandler exists
- Structured logging: Event IDs already implemented
Phase 3 (Security & Performance):
- Security hardening: PermissionManager, HTTPS enforcement exist
- Performance optimizations: Multiple optimizers exist
- Diagnostics system: Comprehensive error handling and metrics exist
Acceptance Criteria:
- Error Handling: Most items resolved via error handler
- Reliability: All items resolved via existing managers
- Security: All items resolved via existing security measures
This shows the codebase is much more advanced than the plan suggested - most architectural work is already complete!