Handle protected daily notes across lock and activation

[syamaner]

Issue

Implements the software and synthetic acceptance work for #51. The real iPhone lock-cycle observation remains a separate device gate.

Changes

• Classify unavailable protected data separately from corrupt or ordinary failed notes I/O, before checking whether the file exists.
• Keep an unsaved draft and the last persisted document distinct; reload after unlock and save the draft only when the on-disk baseline still matches. Fail closed on a conflicting revision.
• Retry on protected-data availability, app activation, or explicit user action. Show temporary unavailability and disable note edits and export of a prepared preview while storage is inaccessible.
• Preserve complete file protection and the existing local-only notes boundary.

Validation

• 249 unsigned iPhone 16 Pro simulator tests passed, including synthetic protected read/write, debounce, background/activation, conflicting revision and export-preparation cases.
• Coverage gate passed: models, formatting and presentation 96.50% (minimum 95%).
• Xcode static analysis passed; project plist lint and git diff --check passed.

No physical lock cycle, personal HealthKit data, OAuth or Drive action was used. Issue #51 should remain open until a separately authorised iPhone check confirms the real protected-data lifecycle.

[codecov]

Codecov Report

❌ Patch coverage is 62.74510% with 57 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
WeeklyHealthReport/Views/DailyNotesView.swift	0.00%	27 Missing ⚠️
...eeklyHealthReport/Notes/DailyNotesController.swift	77.52%	20 Missing ⚠️
WeeklyHealthReport/Views/DailyExportView.swift	0.00%	5 Missing ⚠️
WeeklyHealthReport/Notes/DailyNotesStore.swift	86.95%	3 Missing ⚠️
WeeklyHealthReport/WeeklyHealthReportApp.swift	75.00%	2 Missing ⚠️

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