fix: 修复审查发现的 4 个高优先级问题

- plan: getTodayTarget 补 customPlans 参数,timer/index 调用点传值,修复自定义计划每日目标失效
- leaderboard: fetchRank 加请求序列号丢弃过期响应,修复快速切换周期竞态
- leaderboard 云函数:遍历记录加防御(r.date/duration/数组校验),避免单条脏数据崩溃全榜
- tts: _upload cloudPath 补 volume/speed,避免不同音量语速音频互相覆盖

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

cloudfunctions/leaderboard/index.js

@@ -107,15 +107,21 @@ exports.main = async (event) => {
 
     for (const monthKey of Object.keys(records)) {
       if (prefix && !monthKey.startsWith(prefix)) continue
-      for (const r of records[monthKey]) {
+      const arr = records[monthKey]
+      if (!Array.isArray(arr)) continue
+      for (const r of arr) {
+        // 防御脏数据:r.date 缺失/非字符串、duration 非数字时跳过,
+        // 避免单条坏记录抛 TypeError 导致整个排行榜对所有人失败
+        if (!r || typeof r.date !== 'string') continue
+        const dur = Number(r.duration) || 0
         if (period === 'day') {
           // Use startsWith rather than === to tolerate date strings with
           // trailing time/zone info (e.g. "2026-06-11T09:11:24.587Z" if
           // some legacy path stored an ISO date) and to be timezone-
           // agnostic when client local date differs from server UTC date.
-          if (r.date.startsWith(exact)) { duration += r.duration; sessions++ }
+          if (r.date.startsWith(exact)) { duration += dur; sessions++ }
         } else {
-          if (r.date.startsWith(prefix)) { duration += r.duration; sessions++ }
+          if (r.date.startsWith(prefix)) { duration += dur; sessions++ }
         }
       }
     }