Support ESPHome BLE proxies via HA Bluetooth subsystem

Use async_ble_device_from_address() to resolve the BMS through whichever
adapter (local or ESPHome proxy) can reach it, instead of connecting by
raw MAC address directly. BleakClient now receives a BLEDevice object.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

custom_components/xiaoxiang_bms/bluetooth_handler.py

@@ -6,6 +6,7 @@ import logging
 import struct
 
 from bleak import BleakClient, BleakError
+from bleak.backends.device import BLEDevice
 
 from .const import (
     FRAME_END,
@@ -42,13 +43,17 @@ class BmsBluetoothHandler:
     def is_connected(self) -> bool:
         return self._client is not None and self._client.is_connected
 
-    async def connect(self) -> None:
-        """Open BLE connection and start notifications."""
+    async def connect(self, ble_device: BLEDevice) -> None:
+        """Open BLE connection and start notifications.
+
+        Accepts a BLEDevice resolved by HA's Bluetooth subsystem so that
+        ESPHome BLE proxies are used transparently alongside local adapters.
+        """
         if self.is_connected:
             return
-        _LOGGER.debug("Connecting to BMS at %s", self._address)
+        _LOGGER.debug("Connecting to BMS at %s (via %s)", self._address, ble_device.name)
         self._client = BleakClient(
-            self._address,
+            ble_device,
             disconnected_callback=self._on_disconnect,
         )
         await self._client.connect()