feat(task): introduce task timeout configuration and cleanup unfinished tasks

- Added TaskTimeoutMinutes constant to configure the timeout duration for asynchronous tasks.
- Implemented sweepTimedOutTasks function to identify and handle unfinished tasks that exceed the timeout limit, marking them as failed and processing refunds if applicable.
- Enhanced task polling loop to include the new timeout handling logic, ensuring timely cleanup of stale tasks.

service/task_polling.go

@@ -35,12 +35,65 @@ type TaskPollingAdaptor interface {
 // 打破 service -> relay -> relay/channel -> service 的循环依赖。
 var GetTaskAdaptorFunc func(platform constant.TaskPlatform) TaskPollingAdaptor
 
+// sweepTimedOutTasks 在主轮询之前独立清理超时任务。
+// 每次最多处理 100 条，剩余的下个周期继续处理。
+// 使用 per-task CAS (UpdateWithStatus) 防止覆盖被正常轮询已推进的任务。
+func sweepTimedOutTasks(ctx context.Context) {
+	if constant.TaskTimeoutMinutes <= 0 {
+		return
+	}
+	cutoff := time.Now().Unix() - int64(constant.TaskTimeoutMinutes)*60
+	tasks := model.GetTimedOutUnfinishedTasks(cutoff, 100)
+	if len(tasks) == 0 {
+		return
+	}
+
+	const legacyTaskCutoff int64 = 1740182400 // 2026-02-22 00:00:00 UTC
+	reason := fmt.Sprintf("任务超时（%d分钟）", constant.TaskTimeoutMinutes)
+	legacyReason := "任务超时（旧系统遗留任务，不进行退款，请联系管理员）"
+	now := time.Now().Unix()
+	timedOutCount := 0
+
+	for _, task := range tasks {
+		isLegacy := task.SubmitTime > 0 && task.SubmitTime < legacyTaskCutoff
+
+		oldStatus := task.Status
+		task.Status = model.TaskStatusFailure
+		task.Progress = "100%"
+		task.FinishTime = now
+		if isLegacy {
+			task.FailReason = legacyReason
+		} else {
+			task.FailReason = reason
+		}
+
+		won, err := task.UpdateWithStatus(oldStatus)
+		if err != nil {
+			logger.LogError(ctx, fmt.Sprintf("sweepTimedOutTasks CAS update error for task %s: %v", task.TaskID, err))
+			continue
+		}
+		if !won {
+			logger.LogInfo(ctx, fmt.Sprintf("sweepTimedOutTasks: task %s already transitioned, skip", task.TaskID))
+			continue
+		}
+		timedOutCount++
+		if !isLegacy && task.Quota != 0 {
+			RefundTaskQuota(ctx, task, reason)
+		}
+	}
+
+	if timedOutCount > 0 {
+		logger.LogInfo(ctx, fmt.Sprintf("sweepTimedOutTasks: timed out %d tasks", timedOutCount))
+	}
+}
+
 // TaskPollingLoop 主轮询循环，每 15 秒检查一次未完成的任务
 func TaskPollingLoop() {
 	for {
 		time.Sleep(time.Duration(15) * time.Second)
 		common.SysLog("任务进度轮询开始")
 		ctx := context.TODO()
+		sweepTimedOutTasks(ctx)
 		allTasks := model.GetAllUnFinishSyncTasks(constant.TaskQueryLimit)
 		platformTask := make(map[constant.TaskPlatform][]*model.Task)
 		for _, t := range allTasks {