fix: distinguish task deadlines from child operation timeouts

internal/handler/batch_queue_executor.go

@@ -385,7 +385,7 @@ func (h *AgentHandler) handleBatchSubTaskRunError(
 		strings.Contains(strings.ToLower(errStr), "context canceled") ||
 		strings.Contains(strings.ToLower(errStr), "context cancelled") ||
 		(partialResp != "" && (strings.Contains(partialResp, "任务已被取消") || strings.Contains(partialResp, "任务执行中断")))
-	isTimeout := errors.Is(runErr, context.DeadlineExceeded) || errors.Is(context.Cause(taskCtx), context.DeadlineExceeded)
+	isTimeout := taskDeadlineExceeded(taskCtx)
 
 	if isTimeout {
 		*finishStatus = "timeout"