feat: support FFE4 19-byte format with fitting and run_state fields

Per 协议简述(3): FFE4 now 19 bytes — adds Byte17 fitting status
(0=not fitted, 1=fitted) and Byte18 run state (0=IDLE, 1=scanning,
2=treating, FF=fault). Maintains backward compat with 17-byte format.

miniprogram/services/ble/connection.js

@@ -98,8 +98,14 @@ function handleValueChange(res) {
         console.warn('[BLE] ADC checksum mismatch, dropping')
         return
       }
-      emit('adc', { pd: parsed.pd, vbat: vbatMv, battery: batteryPct })
+      emit('adc', { pd: parsed.pd, vbat: vbatMv, battery: batteryPct, fitting: parsed.fitting, run_state: parsed.run_state })
       emit('battery', { battery: batteryPct, vbat: vbatMv })
+      if (parsed.fitting !== -1) {
+        emit('fitting', { fitting: parsed.fitting })
+      }
+      if (parsed.run_state !== -1) {
+        emit('run_state', { run_state: parsed.run_state })
+      }
       return
     }