Remove redundant notifications.spec.ts from enhancement list

The suggested notifications.spec.ts E2E tests for notification preferences
are already thoroughly covered by existing settings.spec.ts tests which
validate notification time and timezone input, validation, and persistence.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

IMPLEMENTATION_PLAN.md

@@ -121,10 +121,7 @@ All P0-P5 items are complete. The project is feature complete.
 
 These are optional enhancements to improve E2E coverage. Not required for feature completeness.
 
-### New Test Files (Lower Priority)
-| File | Tests | Description |
-|------|-------|-------------|
-| notifications.spec.ts | 3 | Notification preferences |
+**Note:** `notifications.spec.ts` was considered but determined to be redundant with existing `settings.spec.ts` coverage which already tests notification time and timezone preferences thoroughly.
 
 ### Completed Enhancements
 | File | Tests Added | Focus Area |
@@ -150,6 +147,7 @@ These are optional enhancements to improve E2E coverage. Not required for featur
 
 ## Revision History
 
+- 2026-01-13: Marked notifications.spec.ts as redundant (notification preferences already covered in settings.spec.ts)
 - 2026-01-13: Added dark-mode.spec.ts with 2 E2E tests (system preference detection for light/dark mode)
 - 2026-01-13: Added 4 Garmin E2E tests (network error recovery for save, disconnect, status fetch, retry)
 - 2026-01-13: Added 8 E2E tests (calendar accessibility, settings error recovery, calendar mobile behavior)