- Add client struct with conn and room fields
- Add broadcastMsg struct with room and data fields
- Change Hub.clients to Hub.rooms map[string]map[*websocket.Conn]bool
- Add Hub.connRoom map[*websocket.Conn]string for reverse lookup
- Change broadcast channel type to chan broadcastMsg
- Change register channel type to chan client
- Update New() to initialize rooms and connRoom maps
- Update ClientCount() to use len(h.connRoom)
- Add RoomCount() method
- Update Run() loop for room-segmented register/unregister/broadcast
- Update HandleWebSocket to extract room from query param
- Backward compatible: clients without ?room use default empty room
- Update TestNew to verify rooms and connRoom maps initialized
- Add TestRoomCount to verify initial room count is 0
- Fix TestBroadcastChannel to use broadcastMsg type
All existing unit and integration tests pass (16 hub tests + 21 other).
🤖 Assisted by the code-assist SOP
03f379c73c