## 배경 Avatar 컴포넌트를 구현합니다. - size: 'sm' <img width="217" alt="Image" src="https://github.com/user-attachments/assets/4deaf913-cc03-463c-9bb2-16bba32fef2c" /> - size: 'lg' <img width="304" alt="Image" src="https://github.com/user-attachments/assets/8eb68456-f86f-4d7e-8971-d6e87bdd84dc" /> ## ✅ TODO - [x] Avatar 컴포넌트 구현
