feat: improve project agent onboarding

tests/unit/coding-chat-panel.test.tsx

@@ -80,8 +80,8 @@ const agent: CodingProjectAgent = {
   pinned: true,
   createdAt: '2026-08-23T00:00:00.000Z',
   updatedAt: '2026-08-23T00:00:00.000Z',
-  model: null,
-  modelResolution: 'required',
+  model: { accountId: 'account-1', modelId: 'model-1', thinkingLevel: 'off' },
+  modelResolution: 'resolved',
 };
 const config: CodingProjectConfig = {
   schemaVersion: 2,
@@ -199,6 +199,24 @@ describe('CodingChatPanel first Conversation', () => {
     vi.resetModules();
   });
 
+  it('shows an actionable setup state when the active project has no usable Agent', async () => {
+    projectApi.list.mockResolvedValue({ projects: [project], activeProjectId: project.id });
+    projectApi.config.mockResolvedValue({ project, config: configForAgents([]) });
+    projectApi.conversations.mockResolvedValue([]);
+    const onOpenProjectSettings = vi.fn();
+    const { CodingChatPanel } = await import('@/pages/Chat/CodingChatPanel');
+
+    render(<CodingChatPanel onOpenProjectSettings={onOpenProjectSettings} />);
+
+    expect(await screen.findByTestId('coding-chat-agent-setup-empty-state')).toBeVisible();
+    expect(screen.getByText('创建项目智能体后开始对话')).toBeVisible();
+    expect(screen.queryByRole('textbox')).not.toBeInTheDocument();
+    expect(projectApi.create).not.toHaveBeenCalled();
+    expect(conversationApi.snapshot).not.toHaveBeenCalled();
+    fireEvent.click(screen.getByRole('button', { name: '创建或恢复项目智能体' }));
+    expect(onOpenProjectSettings).toHaveBeenCalledOnce();
+  });
+
   it('makes the first-Conversation textarea editable while runtime metadata is held', async () => {
     projectApi.list.mockResolvedValue({ projects: [project], activeProjectId: project.id });
     projectApi.config.mockResolvedValue({ project, config });