feat: complete Phase 1 - game library, lifecycle, realtime sync

- Seed 33 popular games across 5 platforms via admin API script
- Add GameDetailDialog with game info and quick-team button
- Update GamesLibrary with game card click to open detail dialog
- Update Home hot games to open detail dialog instead of navigating
- Rewrite invitation accept: frontend auto-joins team + updates status
- Add user status reset on team dissolution (endGame)
- Add start game / dissolve buttons to TeamSessionPanel lifecycle
- Integrate realtime subscriptions in GroupView and Layout
- Add notification store realtime invitation listener
- Add placeholder images for game covers and avatars
- Remove Go hooks, add JS hooks placeholder + Docker mount

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker-compose.backend.yml

@@ -7,6 +7,7 @@ services:
     volumes:
       - ./backend/pb_data:/pb_data
       - ./backend/pb_migrations:/pb_migrations
+      - ./backend/pb_hooks:/pb_hooks
     environment:
       - GO_ENV=production
     restart: unless-stopped