fix: 13项数据存储与排行榜修复

致命修复:
- leaderboard: 日榜日期比较改用 dateOnly() 替代严格全等
- plan: 计划天数计算日期比较改用 dateOnly()
- cloud: pullAll 添加 orderBy('updatedAt','desc') 确保取最新文档避免数据丢失

严重修复:
- cloud: 新增 cancelPendingPush() 防止清除数据后被延迟推送复活
- settings: _doClearData 补充 user_profile 清除, 先取消推送再清除
- app: 云端同步改为时间戳比对策略, 支持跨设备拉取
- app: _restoreFromCloud 增加空数据保护和 profile 恢复
- storage: 记录ID改用时间戳+自增计数器确保唯一性

中等修复:
- cloud: init/_fetchOpenid 日志升级, 新增 syncStatus getter
- leaderboard云函数: 添加90天活跃过滤减少全表扫描
- storage: validateStreak 增加lastDate无记录时的通用修复
- leaderboard页面: 云函数失败时Toast提示用户而非静默降级

轻微修复:
- timer: onUnload 添加 voice.destroy() 释放音频上下文
- records: onLongPressDelete 委托给 onDeleteRecord 消除重复代码

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

pages/settings/settings.js

@@ -202,12 +202,25 @@ Page({
   },
 
   async _doClearData() {
+    // 1. Cancel any pending push BEFORE clearing, to prevent the
+    //    scheduled _doPush from reading the freshly-reset defaults
+    //    and recreating the cloud doc via add().
+    cloud.cancelPendingPush()
+
+    // 2. Clear all local keys (including user_profile which was
+    //    previously missed)
     wx.removeStorageSync('training_records')
     wx.removeStorageSync('current_streak')
     wx.removeStorageSync('user_settings')
     wx.removeStorageSync('app_theme')
     wx.removeStorageSync('custom_plans')
+    wx.removeStorageSync('user_profile')
+
+    // 3. Clear cloud doc (awaited — order matters: clear cloud
+    //    after cancelling push, before resetting defaults)
     try { await cloud.clearAll() } catch (e) {}
+
+    // 4. Reinstate default settings and streak
     wx.setStorageSync('user_settings', {
       planId: 'beginner',
       voiceGuide: true,
@@ -215,15 +228,19 @@ Page({
       planStartDate: storage.getToday()
     })
     wx.setStorageSync('current_streak', { count: 0, lastDate: '' })
+
+    // 5. Reset theme and UI (include nickName/avatarUrl to clear
+    //    profile state now that user_profile is gone)
     themeMod.setTheme('orange')
     this.setData({
       currentPlanId: 'beginner',
       voiceGuide: true,
       vibrate: true,
-      currentThemeId: 'orange'
+      currentThemeId: 'orange',
+      nickName: '',
+      avatarUrl: ''
     })
     themeMod.applyThemeToPage(this)
-    // Reset plans list — custom_plans are gone
     this.setData({ plans: buildPlansList(storage.getCustomPlans()) })
     wx.showToast({ title: '已清除', icon: 'success', duration: 1500 })
   },