use aliyun s3 store for this project

app/auth.py

@@ -84,6 +84,16 @@ async def auth_callback(request: Request, code: str, state: str):
         db.add(user)
         db.commit()
         db.refresh(user)
+        
+        # 异步/同步将头像转存到 S3
+        from app.utils.s3 import upload_google_avatar_to_s3
+        s3_avatar_url = await upload_google_avatar_to_s3(user_info["picture"], str(user.id))
+        
+        # 将更新后的 S3 URL 写回数据库
+        user.avatar = s3_avatar_url
+        db.commit()
+        # 这里不需要再次 refresh，除非后面还要用到更新后的 user 对象
+        # db.refresh(user)
 
     db.close()