Features:
- Photo memory album: upload photos to complete quests, dedicated /album page
- Google OAuth login alongside email/password
- Dark/light theme toggle with system preference fallback
- PWA: manifest, service worker, installable with offline support
- Mobile-responsive route page with Map/Quests tab switching

Improvements:
- Overpass queries use nwr (node/way/relation) for better POI coverage
- Retry with exponential backoff on Overpass and OSRM requests
- AI quest deduplication against curated explore data by proximity
- Completion-aware map markers show photo thumbnails
- Stepped loading progress during quest generation
- 15-second cooldown on AI API calls to protect Gemini quota
- next/image optimization for all Supabase-hosted photos

Polish:
- Error boundaries (error.tsx, global-error.tsx)
- Loading skeletons for all routes
- Per-page SEO metadata via layout.tsx files
- ARIA roles/labels on dialogs, menus, and tab bar
- Tooltip shadow fix for theme consistency

Co-authored-by: Cursor <cursoragent@cursor.com>