feat(rooms): Fix NaN online stats + Add DAARWIZZ CTA on homepage

- Fixed NaN in online stats by using nullish coalescing (?? 0)
- Added members_online, zone, room_type to /api/v1/city/rooms response
- Added DAARWIZZ chat CTA section on homepage with link to city-lobby
- Created task files for next phases:
  - TASK_PHASE_CITY_ROOMS_FINISH_v2.md
  - TASK_PHASE_AGENT_MANAGEMENT_v1.md
  - TASK_PHASE_CITIZENS_DIRECTORY_v1.md

services/city-service/routes_city.py

@@ -1112,6 +1112,9 @@ async def get_city_rooms_api():
                 "matrix_room_id": room.get("matrix_room_id"),
                 "is_public": room.get("is_public", True),
                 "room_role": room.get("room_role"),
+                "members_online": room.get("members_online") or 0,
+                "zone": room.get("zone"),
+                "room_type": room.get("room_type", "city"),
             })
         
         return result