The BMS only allows one simultaneous BLE connection. Keeping a persistent
connection blocked the mobile app from connecting at all.
Changes:
- BmsBluetoothHandler: replace connect()/disconnect()/request() public API
with a single poll() method that owns the full connect→read→disconnect
lifecycle. Connection is held only for the duration of one data fetch.
- Coordinator: gutted connection-state management — _async_update_data now
just calls handler.poll() and processes results. No reconnect loop needed.
- Poll interval defaults: 15s default, 10s min, 300s max. The BLE connect
overhead (~2s) makes sub-10s intervals impractical.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Don't connect eagerly in async_setup — let the first coordinator poll
handle it. If the BMS is out of range at startup, UpdateFailed becomes
ConfigEntryNotReady and HA retries automatically instead of crashing.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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>