feat(timer): 训练到目标时长不再自动结束,支持超长发挥

- Timer: 到时间触发 onGoalReached(提示)而非自动结束,elapsed/overtime
  继续累加直到用户手动停止
- timer: onGoalReached 播 goal 语音 + goalReached 状态;finishTraining
  补 complete 语音;完成弹窗显示"超长发挥 +X 秒"
- wxml: 超时 badge 训练中也显示;新增 goalReached hint 分支
- voice/tts: 新增 goal 语音 prompt(需部署 tts 云函数)
- config: 版本号 v2.5 -> v2.6

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

utils/timer.js

@@ -1,7 +1,7 @@
 class Timer {
   constructor(options = {}) {
     this.onTick = options.onTick || (() => {})
-    this.onComplete = options.onComplete || (() => {})
+    this.onGoalReached = options.onGoalReached || (() => {})
 
     this._duration = 0
     this._remaining = 0
@@ -11,7 +11,7 @@ class Timer {
     this._intervalId = null
     this._running = false
     this._paused = false
-    this._completed = false
+    this._goalReached = false
     this._appShowBound = false
 
     // WeChat freezes setInterval while the mini-program is in background.
@@ -29,7 +29,7 @@ class Timer {
     this._duration = duration
     this._remaining = duration
     this._elapsed = 0
-    this._completed = false
+    this._goalReached = false
     this._running = true
     this._paused = false
     this._startTime = Date.now()
@@ -81,15 +81,18 @@ class Timer {
       duration: this._duration
     })
 
-    if (this._remaining <= 0 && !this._completed) {
-      this._completed = true
-      this.onComplete({ elapsed: this._elapsed, duration: this._duration })
+    // Goal reached: fire once but DON'T stop - the user keeps training past
+    // the target until they manually end. elapsed keeps climbing, so
+    // overtime (elapsed - duration) grows and the UI shows the surplus.
+    if (this._remaining <= 0 && !this._goalReached) {
+      this._goalReached = true
+      this.onGoalReached({ elapsed: this._elapsed, duration: this._duration })
     }
   }
 
   get isRunning() { return this._running && !this._paused }
   get isPaused() { return this._paused }
-  get isCompleted() { return this._completed }
+  get isGoalReached() { return this._goalReached }
   get remaining() { return this._remaining }
   get elapsed() { return this._elapsed }
 }

utils/voice.js

@@ -22,6 +22,7 @@ const PROMPTS = {
   halfway: '已完成一半啦,坚持就是胜利!',
   last30: '最后30秒,保持呼吸,稳住姿势!',
   last10: '最后10秒,再加把劲!',
+  goal: '目标达成,继续挑战!',
   complete: '太棒了!今天的目标已完成,继续加油!'
 }