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>

cloudfunctions/leaderboard/index.js

@@ -61,8 +61,19 @@ exports.main = async (event) => {
 
   const latestByOpenid = new Map()
 
+  // Exclude accounts that haven't synced in 90+ days to bound the scan.
+  // Docs without an updatedAt field (pre-fix legacy) are included as well.
+  const ninetyDaysAgo = new Date(Date.now() - 90 * 24 * 60 * 60 * 1000)
+
   while (true) {
-    const res = await db.collection(COLLECTION).skip(skip).limit(PAGE_SIZE).get()
+    const res = await db.collection(COLLECTION)
+      .where(_.or([
+        { updatedAt: _.gte(ninetyDaysAgo) },
+        { updatedAt: _.exists(false) }
+      ]))
+      .skip(skip)
+      .limit(PAGE_SIZE)
+      .get()
     if (!res.data || res.data.length === 0) break
 
     for (const doc of res.data) {