fix(chat): guard generated title events

src/components/chat/hooks/useAgentChatSession.test.tsx

@@ -61,6 +61,7 @@ describe("useAgentChatSession", () => {
     jest.mocked(streamAgentChat).mockImplementation(async () => undefined);
     deleteChatSession.mockImplementation(async () => undefined);
     saveActiveChatState.mockImplementation(async (state) => state.sessionId);
+    updateChatSessionTitle.mockImplementation(async () => undefined);
   });
 
   it("does not add a new empty session to history until there is actual chat content", async () => {
@@ -522,6 +523,64 @@ describe("useAgentChatSession", () => {
     );
   });
 
+  it("does not apply a late generated title to a newly created session", async () => {
+    listChatSessions.mockResolvedValue([]);
+    let emitStreamEvent: ((event: StreamEvent) => void) | undefined;
+    let resolveStream: (() => void) | undefined;
+    jest.mocked(streamAgentChat).mockImplementationOnce(async ({ onEvent }) => {
+      emitStreamEvent = onEvent;
+      await new Promise<void>((resolve) => {
+        resolveStream = resolve;
+      });
+    });
+
+    const { result } = renderHook(() =>
+      useAgentChatSession({
+        projectId: "project-1",
+        onToolCall: jest.fn(),
+      }),
+    );
+
+    await waitFor(() => expect(result.current.isHydrating).toBe(false));
+
+    await act(async () => {
+      void result.current.sendPrompt("帮我分析一下");
+      await Promise.resolve();
+    });
+
+    act(() => {
+      emitStreamEvent?.({
+        type: "done",
+        sessionId: "old-session",
+      });
+    });
+
+    await waitFor(() => expect(result.current.isStreaming).toBe(false));
+
+    act(() => {
+      result.current.createSession();
+    });
+
+    expect(result.current.sessionTitle).toBe("新对话");
+
+    await act(async () => {
+      emitStreamEvent?.({
+        type: "session_title",
+        sessionId: "old-session",
+        title: "旧请求标题",
+      });
+      resolveStream?.();
+      await Promise.resolve();
+    });
+
+    expect(result.current.sessionTitle).toBe("新对话");
+    expect(updateChatSessionTitle).toHaveBeenCalledWith(
+      "old-session",
+      "旧请求标题",
+      { isTitleManuallyEdited: false },
+    );
+  });
+
   it("asks the backend to undo the previous user turn before regenerating", async () => {
     listChatSessions.mockResolvedValue([]);