fix: wear-check reconnect scans and connects directly

- Retry button disconnects then re-scans for device (no page navigation)
- Prevents duplicate scan with checking guard
- Disconnect before scan with 500ms delay for adapter recovery
- Clears reconnect timer on success/error/unload
- Error text updated to guide user to retry button

miniprogram/pages/wear-check/wear-check.js

@@ -39,7 +39,7 @@ Page({
     self.setData({ checking: true, result: null, error: '' })
 
     if (!ble.isConnected()) {
-      self.setData({ checking: false, result: 'fail', error: '设备未连接，请返回重新连接' })
+      self.setData({ checking: false, result: 'fail', error: '设备未连接，请点击重新连接' })
       return
     }
 
@@ -70,6 +70,8 @@ Page({
 
   onUnload: function () {
     if (this._onStatus) ble.off('status', this._onStatus)
+    clearTimeout(this._reconnectTimer)
+    ble.stopScan()
   },
 
   onNext: function () {
@@ -77,11 +79,33 @@ Page({
   },
 
   onRetry: function () {
-    if (!ble.isConnected()) {
-      wx.navigateBack()
+    var self = this
+    if (self.data.checking) return
+    if (ble.isConnected()) {
+      self.checkWearing()
       return
     }
-    this.checkWearing()
+    self.setData({ checking: true, result: null, error: '', connected: false })
+    clearTimeout(self._reconnectTimer)
+    ble.disconnect()
+    setTimeout(function () {
+      ble.startScan({
+        onFound: function () {},
+        onConnected: function () {
+          clearTimeout(self._reconnectTimer)
+          self.setData({ checking: false, connected: true })
+          self.checkWearing()
+        },
+        onError: function (err) {
+          clearTimeout(self._reconnectTimer)
+          self.setData({ checking: false, result: 'fail', error: err.msg || '连接失败' })
+        }
+      })
+      self._reconnectTimer = setTimeout(function () {
+        ble.stopScan()
+        self.setData({ checking: false, result: 'fail', error: '搜索超时，请确认设备已开机' })
+      }, 15000)
+    }, 500)
   },
 
   onMockWearOk: function () {