wire donation details + fix conflicts, missed button, claim bugs (REP-39/41/49)

[jeannineruiz]

Summary

Supersedes PR #34 (stephenhung/donation-details-photo-upload-flat) with conflict resolution and bug fixes applied on top of current main.

What's included from PR #34

• Real task date/time fetched from API on Enter Details screen
• Real NPO dropdown populated from API
• Photo upload wired up to submission
• Notes TextInput now controlled
• Complete button calls backend

Fixes applied on top

• Missed button now calls PATCH /api/tasks/:id/mark_as_failed instead of just showing a toast
• Claim button restored isClaiming disabled state to prevent double-tap
• Removed console.log statements from handleClaim
• Removed Undo banner (unclaim not implemented yet)
• Removed mock fallback on API error in pickup-details (shows error state instead) — mock kept temporarily for testing, remove before final merge
• Added missing date helpers (fmt12, formatPickupDate, formatTimeRangeAny, parseHMAny) to dateHelpers.ts which the PR referenced but never defined
• TypeScript + lint fixes throughout

Known limitations

• Complete and Missed will fail on staging until backend PRs #2804 and #2803 are merged (encrypted ID decryption + photo attachment)
• Mock task in pickup-details should be removed before final merge