修复侧边栏按钮在非首页页面仍显示的问题

- 离开首页时 (onHide) 隐藏侧边栏按钮
- 返回首页时 (onShow) 恢复保存的按钮状态

pages/index/index.js

@@ -224,9 +224,21 @@ Page({
     const app = getApp();
     app.updateCurrentTab('index');
     app.globalData.showTabBar = true;
+    
+    const savedBtnHidden = wx.getStorageSync('sidebarBtnHidden');
+    this.setData({
+      sidebarBtnHidden: savedBtnHidden || false
+    });
+    
     this.checkAndRestoreLoginStatus()
   },
 
+  onHide: function () {
+    this.setData({
+      sidebarBtnHidden: true
+    });
+  },
+
   onPullDownRefresh: function() {
     this.onRefresh()
   },