ui: match Agents entry artwork to module cards

tests/unit/module-navigation.test.tsx

@@ -90,6 +90,8 @@ describe('AI module navigation', () => {
     expect(robotOption).toHaveTextContent('Robot 机器');
     expect(robotOption).toHaveTextContent('制作你的第一个机器人小伙伴');
     expect(screen.getByAltText('青少年管理机器人硬件与设备绑定')).toBeInTheDocument();
+    expect(screen.getByAltText('个人云智能体')).toHaveAttribute('src', expect.stringContaining('module-agents.webp'));
+    expect(screen.getByAltText('个人云智能体')).toHaveClass('module-option-card-image-media', 'object-cover');
 
     fireEvent.click(screen.getByTestId('ai-module-option-painting'));
     expect(await screen.findByTestId('location-path')).toHaveTextContent('/image-canvas');