fix(design): surface incomplete creation plans

tests/unit/image-canvas-page.test.tsx

@@ -192,6 +192,40 @@ describe('AI Design Canvas page', () => {
     expect(screen.queryByTestId('image-workspace-works-rail')).not.toBeInTheDocument();
   });
 
+  it('shows an incomplete meaningful plan and does not invent a selected aspect ratio', async () => {
+    const form = designFormFixture();
+    form.specification.values.content.concept = null;
+    form.specification.values.content.action = '一只狗和一只猫在草地上互相扑咬玩闹';
+    form.specification.values.output.aspect_ratio = null;
+    form.specification.values.output.orientation = 'portrait';
+    const { actions } = prepareWorkspace({ form });
+    useImageWorkspaceStore.setState({
+      quoteBlockers: [{
+        code: 'aspect_ratio_required',
+        message: 'Choose an aspect ratio before requesting a production quote.',
+        severity: 'blocker',
+        path: 'output.aspect_ratio',
+      }],
+    });
+
+    render(<ImageCanvas />);
+
+    expect(screen.getByRole('heading', { name: '制作方案' })).toBeInTheDocument();
+    expect(screen.getByText('先选择作品形状。')).toBeInTheDocument();
+    expect(screen.getByRole('combobox', { name: '画幅' })).toHaveValue('');
+    expect(screen.getByRole('button', { name: '准备制作方案' })).toBeDisabled();
+
+    fireEvent.change(screen.getByRole('combobox', { name: '画幅' }), {
+      target: { value: '9:16' },
+    });
+    await waitFor(() => {
+      expect(actions.applyFieldOperations).toHaveBeenCalledWith([
+        { kind: 'set', path: 'output.aspect_ratio', value: '9:16' },
+        { kind: 'set', path: 'output.orientation', value: 'portrait' },
+      ]);
+    });
+  });
+
   it('opens project navigation as a left sheet on compact layouts', () => {
     prepareWorkspace();
     render(<ImageCanvas />);