fix: preserve conversation title after failed first generation

backend/internal/application/conversation/service_message_send.go

@@ -376,6 +376,7 @@ func (s *Service) sendMessageInternal(
 		userMessage.SourcePublicID = branchState.SourcePublicID
 		assistantMessage.ParentPublicID = userMessage.PublicID
 	}
+	s.persistInitialConversationFallbackTitle(ctx, *conversation, *userMessage)
 	traceRecorder = newMessageTraceRecorder(s, ctx, assistantMessage, input.OnEvent)
 
 	if s.routeResolver == nil || s.llmClient == nil {

backend/internal/application/conversation/service_metadata.go

@@ -434,6 +434,40 @@ func (s *Service) persistConversationFallbackTitle(
 	}
 }
 
+func (s *Service) persistInitialConversationFallbackTitle(
+	ctx context.Context,
+	conversation model.Conversation,
+	currentUserMessage model.Message,
+) {
+	if !shouldAutoReplaceConversationTitle(conversation.Title) {
+		return
+	}
+	candidate := currentUserMessage
+	messages, err := s.repo.ListAllMessages(ctx, conversation.ID)
+	if err != nil {
+		if s.logger != nil {
+			s.logger.Warn("conversation_initial_title_message_load_failed",
+				zap.Uint("conversation_id", conversation.ID),
+				zap.Error(err),
+			)
+		}
+		return
+	}
+	if firstUserMessage, ok := firstTitleableConversationUserMessage(messages); ok {
+		candidate = firstUserMessage
+	}
+	s.persistConversationFallbackTitle(ctx, conversation, candidate)
+}
+
+func firstTitleableConversationUserMessage(messages []model.Message) (model.Message, bool) {
+	for _, message := range messages {
+		if message.Role == "user" && strings.TrimSpace(message.Content) != "" {
+			return message, true
+		}
+	}
+	return model.Message{}, false
+}
+
 func renderConversationMetadataPrompt(raw string, fallback string, messages string) string {
 	prompt := strings.TrimSpace(raw)
 	if prompt == "" {

backend/internal/application/conversation/service_metadata_test.go

@@ -1,13 +1,36 @@
 package conversation
 
 import (
+	"context"
 	"errors"
 	"strings"
 	"testing"
 
 	model "github.com/DEEIX-AI/DEEIX-Chat/backend/internal/domain/conversation"
+	"github.com/DEEIX-AI/DEEIX-Chat/backend/internal/repository"
 )
 
+type initialFallbackTitleRepositoryStub struct {
+	repository.ConversationRepository
+	messages  []model.Message
+	patch     repository.ConversationMetadataPatch
+	listCalls int
+}
+
+func (s *initialFallbackTitleRepositoryStub) ListAllMessages(context.Context, uint) ([]model.Message, error) {
+	s.listCalls++
+	return append([]model.Message(nil), s.messages...), nil
+}
+
+func (s *initialFallbackTitleRepositoryStub) UpdateConversationMetadata(
+	_ context.Context,
+	conversationID uint,
+	patch repository.ConversationMetadataPatch,
+) (*model.Conversation, error) {
+	s.patch = patch
+	return &model.Conversation{ID: conversationID, Title: patch.Title}, nil
+}
+
 func TestBuildConversationMetadataMessagesTruncatesToBudget(t *testing.T) {
 	userMsg := model.Message{Content: strings.Repeat("用户输入内容", 6000)}
 
@@ -136,6 +159,46 @@ func TestConversationFallbackTitlePatchOnlyReplacesPlaceholder(t *testing.T) {
 	}
 }
 
+func TestPersistInitialConversationFallbackTitleUsesFirstStoredUserMessage(t *testing.T) {
+	repo := &initialFallbackTitleRepositoryStub{messages: []model.Message{
+		{ID: 1, Role: "user", Content: "第一条失败消息", Status: "error"},
+		{ID: 2, Role: "assistant", Status: "error"},
+		{ID: 3, Role: "user", Content: "第二条成功消息", Status: "pending"},
+	}}
+	service := &Service{repo: repo}
+	service.persistInitialConversationFallbackTitle(
+		t.Context(),
+		model.Conversation{ID: 1, Title: "新对话", MessageCount: 2},
+		model.Message{ID: 3, Role: "user", Content: "第二条成功消息"},
+	)
+
+	if repo.patch.Title != "第一条失败消息" {
+		t.Fatalf("expected the first failed user message to remain the fallback title, got %q", repo.patch.Title)
+	}
+	if repo.listCalls != 1 {
+		t.Fatalf("expected existing conversation history to be loaded once, got %d", repo.listCalls)
+	}
+}
+
+func TestPersistInitialConversationFallbackTitleUsesCurrentFirstMessage(t *testing.T) {
+	repo := &initialFallbackTitleRepositoryStub{messages: []model.Message{{
+		ID: 1, Role: "user", Content: "第一条消息", Status: "pending",
+	}}}
+	service := &Service{repo: repo}
+	service.persistInitialConversationFallbackTitle(
+		t.Context(),
+		model.Conversation{ID: 1, Title: "新对话", MessageCount: 0},
+		model.Message{ID: 1, Role: "user", Content: "第一条消息"},
+	)
+
+	if repo.patch.Title != "第一条消息" {
+		t.Fatalf("expected current first user message as fallback title, got %q", repo.patch.Title)
+	}
+	if repo.listCalls != 1 {
+		t.Fatalf("expected the persisted first message to be loaded once, got %d calls", repo.listCalls)
+	}
+}
+
 func TestFallbackTitleSettlementOnlyRunsForCanceledGeneration(t *testing.T) {
 	userMsg := &model.Message{Content: "首条用户消息"}
 	if !shouldPersistConversationFallbackTitleAfterSend(ErrMessageGenerationCanceled, userMsg) {

frontend/features/chat/hooks/use-chat-message-submit.ts

@@ -1398,6 +1398,21 @@ export function useChatMessageSubmit({
           },
         }));
         toast.error(t("sendFailed"), { description: errorSummary });
+        if (targetConversationID) {
+          const failedConversationID = targetConversationID;
+          void resolveAccessToken()
+            .then((latestToken) =>
+              latestToken ? getConversation(latestToken, failedConversationID) : null,
+            )
+            .then((latestConversation) => {
+              if (latestConversation) {
+                touchByPublicID(failedConversationID, latestConversation);
+              }
+            })
+            .catch(() => {
+              // The next conversation list load will reconcile a failed refresh.
+            });
+        }
         if (targetConversationID && conversationScopeKeyRef.current === targetConversationScopeKey) {
           reload();
         }