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/tts/index.js

@@ -61,8 +61,9 @@ const _synthesize = async (text, promptKey, opts) => {
   return Buffer.from(res.Audio, 'base64')
 }
 
-const _upload = async (key, buffer, voiceType) => {
-  const cloudPath = `${CACHE_DIR}/${key}-${voiceType || 'default'}.mp3`
+const _upload = async (key, buffer, voiceType, volume, speed) => {
+  // cloudPath 含 volume/speed,避免不同音量/语速的音频互相覆盖(缓存碰撞)
+  const cloudPath = `${CACHE_DIR}/${key}-${voiceType || 'default'}-v${volume != null ? volume : 0}-s${speed != null ? speed : 0}.mp3`
   // uploadFile returns the canonical fileID (e.g. "cloud://env.xxx/...").
   // We must use THAT — not the relative cloudPath we passed in — when
   // calling getTempFileURL. A self-constructed fileID is invalid.
@@ -94,7 +95,7 @@ exports.main = async (event) => {
   // Slow path: synthesize + upload + return fresh fileID for caching
   try {
     const buffer = await _synthesize(text, promptKey, { voiceType, volume, speed })
-    const newFileID = await _upload(promptKey, buffer, voiceType)
+    const newFileID = await _upload(promptKey, buffer, voiceType, volume, speed)
     const urlRes = await cloud.getTempFileURL({ fileList: [newFileID] })
     const url = urlRes.fileList[0].tempFileURL
     if (!url) {