refactor(photos): remove NestJS backend, use local-first + direct mana-media

The Photos NestJS backend was a proxy to mana-media that enriched
responses with local album/favorite/tag data. Now:

- Albums store → local-first via albumCollection + albumItemCollection
- Favorites → local-first via favoriteCollection (toggle in IndexedDB)
- Photo tags → local-first via photoTagCollection
- Photo listing/stats → direct mana-media API calls from frontend
- Upload → direct mana-media upload from frontend
- Delete → direct mana-media delete from frontend

Removed 27 TypeScript files, 1 Docker container, 1 port (3039).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker/prometheus/prometheus.yml

@@ -109,12 +109,7 @@ scrape_configs:
     metrics_path: '/metrics'
     scrape_interval: 30s
 
-  # Photos Backend
-  - job_name: 'photos-backend'
-    static_configs:
-      - targets: ['photos-backend:3039']
-    metrics_path: '/metrics'
-    scrape_interval: 30s
+  # Photos Backend: REMOVED — migrated to local-first + direct mana-media
 
   # Zitare Backend: REMOVED — migrated to local-first