add websocket market

app/api/marketplace_ws.py

@@ -0,0 +1,19 @@
+from fastapi import APIRouter, WebSocket, WebSocketDisconnect, Query
+from app.realtime.marketplace_hub import marketplace_hub
+
+router = APIRouter(tags=["Marketplace WS"])
+
+@router.websocket("/ws/marketplace")
+async def marketplace_ws(
+    websocket: WebSocket,
+    server_ip: str = Query(...),
+):
+    await marketplace_hub.connect(server_ip, websocket)
+    try:
+        # Можно принимать сообщения от клиента, но нам не обязательно.
+        while True:
+            await websocket.receive_text()
+    except WebSocketDisconnect:
+        pass
+    finally:
+        await marketplace_hub.disconnect(server_ip, websocket)