chore: import upstream snapshot with attribution

server/routes/websocket.py

@@ -0,0 +1,19 @@
+"""WebSocket endpoint routing."""
+
+from fastapi import APIRouter, WebSocket, WebSocketDisconnect
+
+from server.state import get_websocket_manager
+
+router = APIRouter()
+
+
+@router.websocket("/ws")
+async def websocket_endpoint(websocket: WebSocket, session_id: str = ""):
+    manager = get_websocket_manager()
+    sid = await manager.connect(websocket, session_id=session_id or None)
+    try:
+        while True:
+            message = await websocket.receive_text()
+            await manager.handle_message(sid, message)
+    except WebSocketDisconnect:
+        manager.disconnect(sid)