fix(lefu): 完善蓝牙连接状态处理，修复断开后 UI 不同步问题

- connectState 回调增加 UNAVAILABLE 清理和 READY 自动重连
- disconnect() 增加 _intentionalConnect 标记避免误重连
- deviceWillDisconnect 增加 _activeProtocol 防重入判断
- connectedDevice/equipment/connectedWifi 增加断开状态响应
- connectedWifi 设备断开后自动退出配网页

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

miniprogram/pages/connectedDevice/connectedDevice.ts

@@ -28,6 +28,11 @@ Page({
 
     onShow() {
         console.log(TAG, 'onShow')
+        // 回到页面时同步实际连接状态，避免回调被其他页面覆盖导致状态不同步
+        if (!lefuService.isConnected) {
+            const list = this.data.deviceList.map(item => ({ ...item, connected: false }))
+            this.setData({ deviceList: list })
+        }
     },
 
     onHide() {
@@ -169,6 +174,10 @@ Page({
             this.setData({ _autoConnectTried: true })
             this._autoConnectByIndex(matchedIndex)
         })
+        lefuService.onDisconnected(() => {
+            const list = this.data.deviceList.map(item => ({ ...item, connected: false }))
+            this.setData({ deviceList: list })
+        })
         lefuService.startScan()
         console.log(TAG, 'lefuService.startScan() 已调用')
     },