feat(ios): enhance background task handlers and documentation

Enhance background task handlers with recovery logic and comprehensive
code documentation:

Background Task Handlers (Section 3.3):
- Enhance handleBackgroundFetch with recovery logic:
  - Verify scheduled notifications after fetch
  - Schedule next background task automatically
  - Improved expiration handling with graceful cleanup
- Enhance handleBackgroundNotify with recovery logic:
  - Verify scheduled notifications state
  - Prepare for next task scheduling
  - Improved expiration handling with graceful cleanup
- Add getNextScheduledNotificationTime() helper method
  - Wraps scheduler.getNextNotificationTime() with timeout
  - Used for automatic next task scheduling

Code Documentation (Section 10.1):
- Add comprehensive file-level documentation to ReactivationManager:
  - Purpose, features, architecture overview
  - Recovery scenarios supported
  - Error handling approach
  - Thread safety notes
  - Cross-references to requirements docs
- Add detailed method-level documentation:
  - performRecovery(): process, scenarios, error handling
  - detectScenario(): detection logic, error handling
  - performColdStartRecovery(): steps, return values
  - detectMissedNotifications(): criteria, error handling
  - verifyFutureNotifications(): verification process
  - rescheduleMissingNotification(): process, throws
  - handleTerminationRecovery(): comprehensive recovery
  - performBootRecovery(): boot recovery process
  - recordRecoveryHistory(): history recording
  - recordRecoveryFailure(): failure recording
  - detectBootScenario(): detection logic
  - updateLastLaunchTime(): storage details
  - verifyBGTaskRegistration(): diagnostic method
- Add @param, @return, @throws tags to all methods
- Document error handling behavior for all methods

Implementation Status (Section 10.2):
- Update ios/Plugin/README.md with current status:
  - Mark all completed features as ✅
  - Add new components (DAO classes, ReactivationManager)
  - Update version to 1.1.0
  - Add recovery scenarios supported
  - Update architecture overview
  - Add last updated date (2025-12-08)

Completes sections 3.3, 10.1, and 10.2 of iOS implementation checklist.

docs/IOS_IMPLEMENTATION_CHECKLIST.md

@@ -184,13 +184,13 @@ Complete checklist of iOS code that needs to be implemented for feature parity w
 
 ### 3.3 Background Task Handlers
 
-- [ ] Enhance `handleBackgroundFetch` in `DailyNotificationBackgroundTasks.swift`:
-  - [ ] Add recovery logic if needed
-  - [ ] Schedule next background task
-  - [ ] Handle expiration gracefully
-- [ ] Enhance `handleBackgroundNotify`:
-  - [ ] Add recovery logic if needed
-  - [ ] Schedule next background task
+- [x] Enhance `handleBackgroundFetch` in `DailyNotificationPlugin.swift`:
+  - [x] Add recovery logic if needed (verification of scheduled notifications)
+  - [x] Schedule next background task (using getNextScheduledNotificationTime)
+  - [x] Handle expiration gracefully (enhanced expiration handler with cleanup)
+- [x] Enhance `handleBackgroundNotify`:
+  - [x] Add recovery logic if needed (verification of scheduled notifications)
+  - [x] Schedule next background task (helper method added)
 
 ### 3.4 Testing
 
@@ -446,18 +446,18 @@ Complete checklist of iOS code that needs to be implemented for feature parity w
 
 ### 10.1 Code Documentation
 
-- [ ] Add file-level documentation to `DailyNotificationReactivationManager.swift`
-- [ ] Add method-level documentation to all public methods
-- [ ] Add parameter documentation
-- [ ] Add return value documentation
-- [ ] Add error documentation
+- [x] Add file-level documentation to `DailyNotificationReactivationManager.swift`
+- [x] Add method-level documentation to all public methods
+- [x] Add parameter documentation (@param tags)
+- [x] Add return value documentation (@return tags)
+- [x] Add error documentation (@throws tags and error handling notes)
 
 ### 10.2 Implementation Status
 
-- [ ] Update `ios/Plugin/README.md` with implementation status
-- [ ] Mark completed features as ✅
-- [ ] Update version numbers
-- [ ] Update "Last Updated" dates
+- [x] Update `ios/Plugin/README.md` with implementation status
+- [x] Mark completed features as ✅
+- [x] Update version numbers (1.1.0)
+- [x] Update "Last Updated" dates (2025-12-08)
 
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