- Add migration 013_city_map_coordinates.sql with map coordinates, zones, and agents table
- Add /city/map API endpoint in city-service
- Add /city/agents and /city/agents/online endpoints
- Extend presence aggregator to include agents[] in snapshot
- Add AgentsSource for fetching agent data from DB
- Create CityMap component with interactive room tiles
- Add useCityMap hook for fetching map data
- Update useGlobalPresence to include agents
- Add map/list view toggle on /city page
- Add agent badges to room cards and map tiles