firmware: store real wifi_password in config.json

Per maintainer decision: this is a private repo and the closed
travel-router Wi-Fi password is low-sensitivity, so keep the real
value in the tracked config for reproducible uploadfs provisioning.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

firmware/data/config.json

@@ -1,6 +1,6 @@
 {
   "wifi_ssid": "RemoteRig",
-  "wifi_password": "",
+  "wifi_password": "RemoteRig1",
   "mqtt_broker": "192.168.8.56",
   "mqtt_port": 1883,
   "camera_id": "",