ESP factory reset clear NVS too

examples/companion_radio/MyMesh.cpp

@@ -1613,6 +1613,10 @@ void MyMesh::handleCmdFrame(size_t len) {
       writeErrFrame(ERR_CODE_ILLEGAL_ARG); // invalid stats sub-type
     }
   } else if (cmd_frame[0] == CMD_FACTORY_RESET && memcmp(&cmd_frame[1], "reset", 5) == 0) {
+    if (_serial) {
+      MESH_DEBUG_PRINTLN("Factory reset: disabling serial interface to prevent reconnects (BLE/WiFi)");
+      _serial->disable(); // Phone app disconnects before we can send OK frame so it's safe here
+    }
     bool success = _store->formatFileSystem();
     if (success) {
       writeOKFrame();