fix: BLE reconnect stuck on binding state

- onRetry clears bind_result listener before disconnect
- Add 1s delay after closeBluetoothAdapter before re-scanning
- Fix binding state text from '点击连接' to '正在配对...'

miniprogram/pages/ble-connect/ble-connect.wxml

@@ -19,7 +19,7 @@
     <view class="found-card" wx:if="{{state === 'binding'}}">
       <view class="found-icon">💆</view>
       <view class="found-name">光子美容仪-{{deviceId}}</view>
-      <text class="status-badge status-badge-green">点击连接</text>
+      <text class="status-badge status-badge-green">正在配对...</text>
     </view>
 
     <view class="found-card" wx:if="{{state === 'error'}}">