  qs.hdg.textContent = '-';
          qs.battv.textContent = '-';
          qs.battp.textContent = '-';
          qs.mode.textContent = '-';
          qs.gps.textContent = '-';
          qs.ll.textContent = '-';
        }
      }, TRAFFIC_TIMEOUT_MS + 50);
    }

    var telem_roll;

    // ---------- Socket.IO only ----------
    const socket = io(CC_URL, { transports: ["websocket","polling"], timeout: 8000 });

    socket.on("connect", () => {
      console.log("[io] connected", socket.id);
      setConnU