Integrate JBD BMS telemetry into ESP32 status

firmware/esp32/xterra-controller/bms/bms.h

@@ -0,0 +1,22 @@
+#pragma once
+
+struct BmsData {
+    bool connected = false;
+    bool valid = false;
+
+    float soc = 0;
+    float voltage = 0;
+    float current = 0;
+    float remainingAh = 0;
+    float capacityAh = 0;
+    float temperatureF = 0;
+
+    int cycleCount = 0;
+    int cellCount = 0;
+    int ntcCount = 0;
+};
+
+extern BmsData bmsData;
+
+void initBms();
+void updateBms();