fix: 自动标题取消语义、清洗循环与拒绝占位回写

spawn_task 标题 20s 超时且父 ctx 取消不建任务；清洗循环剥前缀内外引号；
异步标题拒绝「新对话」并用条件更新防手改竞态；会话 profile 失败回退全局。

server/auto_title_test.go

@@ -12,3 +12,14 @@ func TestAutoTitleMayReplace(t *testing.T) {
 		t.Fatal("manual title must not be overwritten")
 	}
 }
+
+func TestAutoTitleIsUsable(t *testing.T) {
+	for _, generated := range []string{"", "新对话"} {
+		if autoTitleIsUsable(generated) {
+			t.Fatalf("placeholder title %q must be rejected", generated)
+		}
+	}
+	if !autoTitleIsUsable("整理项目设置") {
+		t.Fatal("generated title should be accepted")
+	}
+}

server/conversations.go

@@ -17,6 +17,7 @@ import (
 	"github.com/Autumn-27/artex/db"
 	"github.com/Autumn-27/artex/intercept"
 	"github.com/Autumn-27/artex/sidequestion"
+	"github.com/Autumn-27/norma/llm"
 )
 
 const (
@@ -469,33 +470,34 @@ func (s *Server) pgSendConversationMessage(w http.ResponseWriter, r *http.Reques
 				ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
 				defer cancel()
 				profileID := s.effectiveProfileForAgent(agentKey, pinnedProfile)
-				if profileID == nil {
-					if active, err := s.m.pg.ActiveProfile(); err == nil && active != nil {
+				var prov llm.Provider
+				providerOK := false
+				if profileID != nil {
+					prov, _, providerOK = s.providerForProfile(*profileID)
+				}
+				if !providerOK {
+					if active, activeErr := s.m.pg.ActiveProfile(); activeErr == nil && active != nil {
 						profileID = &active.ID
+						prov, _, providerOK = s.providerForProfile(active.ID)
+					} else if activeErr != nil {
+						log.Printf("[auto-title] conversation %d active profile lookup failed: %v", conversationID, activeErr)
 					}
 				}
-				if profileID == nil {
+				if profileID == nil || !providerOK || prov == nil {
 					log.Printf("[auto-title] conversation %d: no effective profile", conversationID)
 					return
 				}
-				prov, _, ok := s.providerForProfile(*profileID)
-				if !ok {
-					log.Printf("[auto-title] conversation %d: provider unavailable for profile %d", conversationID, *profileID)
-					return
-				}
 				generated, err := agent.GenerateAutoTitle(ctx, prov, promptContent)
 				if err != nil {
 					log.Printf("[auto-title] conversation %d: %v", conversationID, err)
 					return
 				}
-				current, err := s.m.pg.GetConversation(conversationID)
-				if err != nil || current == nil {
+				if !autoTitleIsUsable(generated) {
+					log.Printf("[auto-title] conversation %d: generated title is empty or placeholder", conversationID)
 					return
 				}
-				if autoTitleMayReplace(current.Title, title) {
-					if err := s.m.pg.RenameConversation(conversationID, generated); err != nil {
-						log.Printf("[auto-title] conversation %d rename failed: %v", conversationID, err)
-					}
+				if err := s.m.pg.RenameConversationIfTitle(conversationID, generated, title); err != nil {
+					log.Printf("[auto-title] conversation %d rename failed: %v", conversationID, err)
 				}
 			}()
 		}
@@ -517,6 +519,10 @@ func autoTitleMayReplace(current, initial string) bool {
 	return current == "" || current == "新对话" || current == initial
 }
 
+func autoTitleIsUsable(generated string) bool {
+	return generated != "" && generated != "新对话"
+}
+
 // runConversation runs ONE agent turn on a conversation in a background goroutine
 // (each conversation is independent → parallel). Steps stream to
 // conversation_activities. Shared by the chat HTTP handler and the P3 scheduler.

server/orchestration.go

@@ -306,17 +306,35 @@ func (s *Server) toolSpawnTask() actool.CoreTool {
 				llmIDs = []int64{*pin}
 			}
 			name := ""
-			if s.m.pg.GetBool(db.SettingTaskAutoTitle, false) {
-				if active, activeErr := s.m.pg.ActiveProfile(); activeErr == nil && active != nil {
-					if prov, _, providerOK := s.providerForProfile(active.ID); providerOK {
-						if generated, titleErr := agent.GenerateAutoTitle(ctx, prov, a.Description+"\n"+a.Goal); titleErr == nil {
-							name = generated
-						} else {
-							log.Printf("[auto-title] task %s: %v", a.Description, titleErr)
-						}
-					} else {
-						log.Printf("[auto-title] task provider unavailable for active profile %d", active.ID)
+			autoTitleEnabled := s.m.pg.GetBool(db.SettingTaskAutoTitle, false)
+			if autoTitleEnabled {
+				if err := ctx.Err(); err != nil {
+					return actool.Errorf(err.Error()), nil
+				}
+				active, activeErr := s.m.pg.ActiveProfile()
+				if activeErr != nil {
+					log.Printf("[auto-title] active profile lookup failed: %v", activeErr)
+				} else if active == nil {
+					log.Printf("[auto-title] no active profile")
+				} else if prov, _, providerOK := s.providerForProfile(active.ID); providerOK {
+					titleCtx, cancel := context.WithTimeout(ctx, 20*time.Second)
+					defer cancel()
+					generated, titleErr := agent.GenerateAutoTitle(titleCtx, prov, a.Description+"\n"+a.Goal)
+					if err := ctx.Err(); err != nil {
+						return actool.Errorf(err.Error()), nil
 					}
+					if titleErr == nil {
+						name = generated
+					} else {
+						log.Printf("[auto-title] task title generation failed: %v", titleErr)
+					}
+				} else {
+					log.Printf("[auto-title] task provider unavailable for active profile %d", active.ID)
+				}
+			}
+			if autoTitleEnabled {
+				if err := ctx.Err(); err != nil {
+					return actool.Errorf(err.Error()), nil
 				}
 			}
 			t, err := s.m.CreateTaskWithOptions(a.Description, a.Goal, db.TaskCreateOptions{