fix(service): ParallelAgent 使用 goroutine 并发执行子 Agent

backend/internal/service/agent.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"strings"
+	"sync"
 	"sync/atomic"
 
 	"ai-agent-scaffold-go/internal/model"
@@ -283,28 +284,67 @@ func (a *ParallelAgent) Stream(ctx context.Context, content model.ChatContent, o
 }
 
 func (a *ParallelAgent) runWithVars(ctx context.Context, content model.ChatContent, vars map[string]string) (string, error) {
+	type result struct {
+		index int
+		name  string
+		text  string
+		err   error
+	}
+
+	results := make([]result, len(a.subAgents))
+	var wg sync.WaitGroup
+
+	for i, sub := range a.subAgents {
+		wg.Add(1)
+		go func(idx int, s workflowSubAgent) {
+			defer wg.Done()
+			text, err := s.runWithVars(ctx, content, vars)
+			results[idx] = result{index: idx, name: s.Name(), text: text, err: err}
+		}(i, sub)
+	}
+	wg.Wait()
+
+	// 按原始顺序组装结果，遇到错误立即返回
 	parts := make([]string, 0, len(a.subAgents))
-	for _, sub := range a.subAgents {
-		text, err := sub.runWithVars(ctx, content, vars)
-		if err != nil {
-			return "", err
+	for _, r := range results {
+		if r.err != nil {
+			return "", r.err
 		}
-		parts = append(parts, fmt.Sprintf("[%s] %s", sub.Name(), text))
+		parts = append(parts, fmt.Sprintf("[%s] %s", r.name, r.text))
 	}
 	return strings.Join(parts, "\n"), nil
 }
 
 func (a *ParallelAgent) streamWithVars(ctx context.Context, content model.ChatContent, out chan<- string, vars map[string]string) error {
-	text, err := a.runWithVars(ctx, content, vars)
-	if err != nil {
+	errCh := make(chan error, len(a.subAgents))
+	var wg sync.WaitGroup
+
+	for _, sub := range a.subAgents {
+		wg.Add(1)
+		go func(s workflowSubAgent) {
+			defer wg.Done()
+			// 流式输出前缀标识
+			prefix := fmt.Sprintf("[%s] ", s.Name())
+			select {
+			case out <- prefix:
+			case <-ctx.Done():
+				errCh <- ctx.Err()
+				return
+			}
+			if err := s.streamWithVars(ctx, content, out, vars); err != nil {
+				errCh <- err
+			}
+		}(sub)
+	}
+
+	wg.Wait()
+	close(errCh)
+
+	// 返回第一个错误（如有）
+	for err := range errCh {
 		return err
 	}
-	select {
-	case out <- text:
-		return nil
-	case <-ctx.Done():
-		return ctx.Err()
-	}
+	return nil
 }
 
 // ============================================================