Add WebSocket support for switch status updates

- Define `LoadSwStatus` protobuf message for switch state data (`main` and `usb`).
- Introduce `updateSwitchStatusUI` to synchronize UI with WebSocket switch status payloads.
- Update backend logic to manage and broadcast switch status changes dynamically.

Signed-off-by: YoungSoo Shin <shinys000114@gmail.com>

page/src/main.js

@@ -19,6 +19,7 @@ import {
     initUI,
     updateControlStatus,
     updateSensorUI,
+    updateSwitchStatusUI,
     updateUptimeUI,
     updateWebsocketStatus,
     updateWifiStatusUI
@@ -85,6 +86,12 @@ function onWsMessage(event) {
                 updateWifiStatusUI(decodedMessage.wifiStatus);
                 break;
 
+            case 'swStatus':
+                if (decodedMessage.swStatus) {
+                    updateSwitchStatusUI(decodedMessage.swStatus);
+                }
+                break;
+
             case 'uartData':
                 if (term && decodedMessage.uartData && decodedMessage.uartData.data) {
                     term.write(decodedMessage.uartData.data);