City Service:
- GET /api/v1/chat/rooms/{room_id}/messages - get message history
- POST /api/v1/chat/rooms/{room_id}/messages - send message
- Add get_room_by_id to repo_city
Synapse:
- Increase rate limits for room creation
- Add rc_joins, rc_invites configuration
All 27 rooms now have matrix_room_id
