feat(lefu): 迁移乐福体脂秤 SDK，接入设备扫描连接与 WiFi 配网

- 新增 lefu 服务层（扫描/连接/断开/保活重连/测量回调/WiFi 配网），事件回调支持多监听
- connectedDevice 接入真实蓝牙扫描连接，修复断线重连 UI 未同步、蓝牙/定位开关误判
- connectedWifi 接入真实 WiFi 配网，补连接状态校验与退出配网模式
- 新增 5 张设备图标并调整应用入口

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

miniprogram/app.json

@@ -1,8 +1,8 @@
 {
 	"pages": [
+		"pages/connectedDevice/connectedDevice",
 		"pages/login/login", 
 		"pages/supplementPersonal/supplementPersonal",
-		"pages/connectedDevice/connectedDevice",
 		"pages/connectedWifi/connectedWifi",
 		"pages/home/home",
 		"pages/detailedReport/detailedReport",