Add runtime UV protection toggle and treat near-zero sense as external power.

Per-pod NVS enable (default off) via UART/ESP-NOW/dashboard, and skip UV latch when LiPo ADC reads ~0 mV so USB/external supply still boots.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/client_api.go

@@ -290,6 +290,44 @@ func (m *managedSerial) tapConfigExchange(poll bool, req *pb.TapConfigRequest) (
 	return r, nil
 }
 
+func (m *managedSerial) BatteryUv(req *pb.BatteryUvRequest) (*pb.BatteryUvResponse, error) {
+	return m.batteryUvExchange(false, req)
+}
+
+func (m *managedSerial) BatteryUvPoll(req *pb.BatteryUvRequest) (*pb.BatteryUvResponse, error) {
+	return m.batteryUvExchange(true, req)
+}
+
+func (m *managedSerial) batteryUvExchange(poll bool, req *pb.BatteryUvRequest) (*pb.BatteryUvResponse, error) {
+	msg := &pb.UartMessage{
+		Type:    pb.MessageType_BATTERY_UV,
+		Payload: &pb.UartMessage_BatteryUvRequest{BatteryUvRequest: req},
+	}
+	body, err := proto.Marshal(msg)
+	if err != nil {
+		return nil, fmt.Errorf("encode: %w", err)
+	}
+	payload := append([]byte{byte(pb.MessageType_BATTERY_UV)}, body...)
+	var respPayload []byte
+	if poll {
+		respPayload, err = m.exchangePayloadPoll(payload, "BATTERY_UV")
+	} else {
+		respPayload, err = m.exchangePayload(payload, "BATTERY_UV")
+	}
+	if err != nil {
+		return nil, err
+	}
+	var respMsg pb.UartMessage
+	if err := proto.Unmarshal(respPayload[1:], &respMsg); err != nil {
+		return nil, fmt.Errorf("decode: %w", err)
+	}
+	r := respMsg.GetBatteryUvResponse()
+	if r == nil {
+		return nil, fmt.Errorf("missing battery_uv_response")
+	}
+	return r, nil
+}
+
 func (m *managedSerial) accelDeadzoneExchange(poll bool, req *pb.AccelDeadzoneRequest) (*pb.AccelDeadzoneResponse, error) {
 	msg := &pb.UartMessage{
 		Type:    pb.MessageType_ACCEL_DEADZONE,
@@ -510,6 +548,33 @@ func (s *serialPort) tapConfig(req *pb.TapConfigRequest) (*pb.TapConfigResponse,
 	return r, nil
 }
 
+func (s *serialPort) batteryUv(req *pb.BatteryUvRequest) (*pb.BatteryUvResponse, error) {
+	msg := &pb.UartMessage{
+		Type: pb.MessageType_BATTERY_UV,
+		Payload: &pb.UartMessage_BatteryUvRequest{
+			BatteryUvRequest: req,
+		},
+	}
+	body, err := proto.Marshal(msg)
+	if err != nil {
+		return nil, fmt.Errorf("encode: %w", err)
+	}
+	payload := append([]byte{byte(pb.MessageType_BATTERY_UV)}, body...)
+	respPayload, err := s.exchangePayload(payload, "BATTERY_UV")
+	if err != nil {
+		return nil, err
+	}
+	var respMsg pb.UartMessage
+	if err := proto.Unmarshal(respPayload[1:], &respMsg); err != nil {
+		return nil, fmt.Errorf("decode: %w", err)
+	}
+	r := respMsg.GetBatteryUvResponse()
+	if r == nil {
+		return nil, fmt.Errorf("missing battery_uv_response")
+	}
+	return r, nil
+}
+
 func (s *serialPort) espnowUnicastTest(clientID, seq uint32) (*pb.EspNowUnicastTestResponse, error) {
 	req := &pb.EspNowUnicastTestRequest{ClientId: clientID, Seq: seq}
 	msg := &pb.UartMessage{
@@ -681,6 +746,10 @@ func (s *serialPort) TapConfig(req *pb.TapConfigRequest) (*pb.TapConfigResponse,
 	return s.tapConfig(req)
 }
 
+func (s *serialPort) BatteryUv(req *pb.BatteryUvRequest) (*pb.BatteryUvResponse, error) {
+	return s.batteryUv(req)
+}
+
 func (s *serialPort) EspnowUnicastTest(clientID, seq uint32) (*pb.EspNowUnicastTestResponse, error) {
 	return s.espnowUnicastTest(clientID, seq)
 }