Full protocol coverage: binary sensors, energy, hardware version

Sensors added:
- energy_stored (kWh = V × Ah / 1000) for energy dashboard

Binary sensors added (all from existing 0x03 frame, no extra BLE requests):
- Charge MOSFET / Discharge MOSFET (MOS gate status)
- Cell Balancing (any balance bit active)
- 13× protection flags: cell/pack over/under-voltage, charge/discharge
  over/under-temperature, charge/discharge over-current, short circuit,
  frontend IC error, software lock

Other:
- Hardware version string fetched once via CMD 0x05, shown in device card
- DeviceInfo centralised on coordinator (sensor + binary_sensor share it)
- CONF_ADDRESS removed from sensor.py (coordinator holds address)

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

custom_components/xiaoxiang_bms/bluetooth_handler.py

@@ -172,6 +172,10 @@ class BmsBluetoothHandler:
             raw = struct.unpack_from(">H", p, 23 + i * 2)[0]
             temperatures.append(round((raw - 2731) / 10.0, 1))
 
+        balance = struct.unpack_from(">H", p, 12)[0] | struct.unpack_from(">H", p, 14)[0]
+        prot    = struct.unpack_from(">H", p, 16)[0]
+        mos     = p[20]
+
         return {
             "voltage":            round(struct.unpack_from(">H", p, 0)[0] / 100.0, 2),
             "current":            round(struct.unpack_from(">h", p, 2)[0] / 100.0, 2),
@@ -181,8 +185,33 @@ class BmsBluetoothHandler:
             "state_of_charge":    p[19],
             "cell_count":         p[21],
             "temperatures":       temperatures,
+            # MOS status
+            "mos_charge_enabled":    bool(mos & 0x01),
+            "mos_discharge_enabled": bool(mos & 0x02),
+            # Cell balancing (any cell currently balancing)
+            "balance_active": balance != 0,
+            # Protection flags (bit per event, True = protection triggered)
+            "prot_cell_overvolt":         bool(prot & (1 << 0)),
+            "prot_cell_undervolt":        bool(prot & (1 << 1)),
+            "prot_pack_overvolt":         bool(prot & (1 << 2)),
+            "prot_pack_undervolt":        bool(prot & (1 << 3)),
+            "prot_charge_overtemp":       bool(prot & (1 << 4)),
+            "prot_charge_undertemp":      bool(prot & (1 << 5)),
+            "prot_discharge_overtemp":    bool(prot & (1 << 6)),
+            "prot_discharge_undertemp":   bool(prot & (1 << 7)),
+            "prot_charge_overcurrent":    bool(prot & (1 << 8)),
+            "prot_discharge_overcurrent": bool(prot & (1 << 9)),
+            "prot_short_circuit":         bool(prot & (1 << 10)),
+            "prot_frontend_ic_error":     bool(prot & (1 << 11)),
+            "prot_software_lock":         bool(prot & (1 << 12)),
         }
 
+    @staticmethod
+    def parse_version(frame: bytes) -> str:
+        """Parse a 0x05 hardware version response frame into an ASCII string."""
+        p = frame[_HEADER_LEN:-_TRAILER_LEN]
+        return p.decode("ascii", errors="replace").strip("\x00").strip()
+
     @staticmethod
     def parse_cell_info(frame: bytes) -> dict:
         """Parse a 0x04 cell voltage response frame.