diff --git a/agent/auto_title.go b/agent/auto_title.go
index 02a94e4..280c9e1 100644
--- a/agent/auto_title.go
+++ b/agent/auto_title.go
@@ -51,22 +51,23 @@ func cleanAutoTitle(raw string) string {
 	if i := strings.IndexAny(title, "\r\n"); i >= 0 {
 		title = strings.TrimSpace(title[:i])
 	}
-	for len(title) >= 2 {
-		first, firstSize := utf8.DecodeRuneInString(title)
-		last, lastSize := utf8.DecodeLastRuneInString(title)
-		if (first == '"' && last == '"') || (first == '\'' && last == '\'') || (first == '“' && last == '”') || (first == '「' && last == '」') {
-			title = strings.TrimSpace(title[firstSize : len(title)-lastSize])
-			continue
+	for {
+		previous := title
+		if len(title) >= 2 {
+			first, firstSize := utf8.DecodeRuneInString(title)
+			last, lastSize := utf8.DecodeLastRuneInString(title)
+			if (first == '"' && last == '"') || (first == '\'' && last == '\'') || (first == '“' && last == '”') || (first == '「' && last == '」') {
+				title = title[firstSize : len(title)-lastSize]
+			}
 		}
-		break
-	}
-	lines := strings.FieldsFunc(title, func(r rune) bool { return r == '\r' || r == '\n' })
-	if len(lines) > 0 {
-		title = strings.TrimSpace(lines[0])
-	}
-	for _, prefix := range []string{"标题：", "标题:"} {
-		if strings.HasPrefix(title, prefix) {
-			title = strings.TrimSpace(strings.TrimPrefix(title, prefix))
+		for _, prefix := range []string{"标题：", "标题:"} {
+			if strings.HasPrefix(title, prefix) {
+				title = strings.TrimPrefix(title, prefix)
+				break
+			}
+		}
+		title = strings.TrimSpace(title)
+		if title == previous {
 			break
 		}
 	}
diff --git a/agent/auto_title_test.go b/agent/auto_title_test.go
index 7041204..b640a76 100644
--- a/agent/auto_title_test.go
+++ b/agent/auto_title_test.go
@@ -41,6 +41,15 @@ func TestGenerateAutoTitleCleansResponse(t *testing.T) {
 	if p.req.Thinking != "disabled" || p.req.MaxTokens != 96 || len(p.req.Tools) != 0 {
 		t.Fatalf("request options: %+v", p.req)
 	}
+
+	quoted := &autoTitleProvider{reply: `标题："整理项目设置"`}
+	got, err = GenerateAutoTitle(t.Context(), quoted, "整理项目设置")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "整理项目设置" {
+		t.Fatalf("nested quote/prefix cleanup: got %q", got)
+	}
 }
 
 func TestGenerateAutoTitleProviderError(t *testing.T) {
diff --git a/db/conversation.go b/db/conversation.go
index 7db9afd..48ede2a 100644
--- a/db/conversation.go
+++ b/db/conversation.go
@@ -197,6 +197,15 @@ func (d *DB) RenameConversation(id int64, title string) error {
 	return err
 }
 
+// RenameConversationIfTitle updates a thread only while its title is still an
+// initial placeholder or preview. This keeps asynchronous auto-title writes
+// from overwriting a concurrent manual rename.
+func (d *DB) RenameConversationIfTitle(id int64, title, initial string) error {
+	_, err := d.Exec(`UPDATE conversations SET title=$2
+WHERE id=$1 AND title IN ('', '新对话', $3)`, id, title, initial)
+	return err
+}
+
 // TouchConversation bumps updated_at so the thread floats to the top of the list.
 func (d *DB) TouchConversation(id int64) error {
 	_, err := d.Exec(`UPDATE conversations SET updated_at=now() WHERE id=$1`, id)
diff --git a/server/auto_title_test.go b/server/auto_title_test.go
index 25b5434..f28a065 100644
--- a/server/auto_title_test.go
+++ b/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")
+	}
+}
diff --git a/server/conversations.go b/server/conversations.go
index 389188a..f396647 100644
--- a/server/conversations.go
+++ b/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.
diff --git a/server/orchestration.go b/server/orchestration.go
index 06d6892..bca694b 100644
--- a/server/orchestration.go
+++ b/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{