Standardize API UART parity and update docs

docs/UART_PROTOCOL.md

@@ -205,3 +205,30 @@ Runtime behavior:
 
     If STA disconnects, the ESP32 retries saved networks by priority every 30 seconds.
     AP mode remains available as a recovery path.
+
+
+---
+
+# UART Parity Notes
+
+UART should use the same generic command model as HTTP.
+
+## Preferred Relay Command
+
+Preferred:
+
+    {"type":"set_relay","id":"relay_1","state":true}
+
+Legacy accepted shape:
+
+    {"type":"set_relay","relay":"relay_1","enabled":true}
+
+Preferred response:
+
+    {"type":"relay_response","ok":true,"id":"relay_1","state":true}
+
+## WiFi Priority Config
+
+    {"type":"config_wifi","networks":[{"ssid":"Starlink","password":"password","priority":1},{"ssid":"Home WiFi","password":"password","priority":2}]}
+
+Lower priority numbers are tried first.