重构表结构：合并 profiles→users，展平 API 响应，新增计数器字段

- models: 删除 Profile 模型，字段合并到 User；User 新增云朵/公开/收藏计数器；Cloud 新增 favorite_count
- schemas/serializers: 展平 UserOut/AuthOut/MeOut/AdminUserOut，移除嵌套 profile
- deps: user.profile.role→user.role，移除 selectinload profile
- auth/register: 注册时直接设置 user 字段，不再创建 Profile
- clouds: 创建/删除云朵时同步 user.cloud_count 计数器，状态变化时同步 public_cloud_count
- favorites: 点赞/取消时同步 cloud.favorite_count 计数器
- admin: 审批/隐藏/批量删时同步 public_cloud_count 计数器
- profiles/stats: 用计数器替代实时 COUNT 查询
- alembic: 新增 migration 合并 profiles 到 users，初始化 counters

app/deps.py

@@ -34,7 +34,6 @@ async def _resolve_user(
             (RefreshSession.id == payload.session_id)
             & (RefreshSession.user_id == User.id),
         )
-        .options(selectinload(User.profile))
         .where(
             User.id == payload.user_id,
             RefreshSession.revoked_at.is_(None),
@@ -44,7 +43,7 @@ async def _resolve_user(
     user = result.scalar_one_or_none()
     if not user:
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="登录状态已失效")
-    if user.profile.is_disabled:
+    if user.is_disabled:
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="账号已被禁用")
     return user
 
@@ -68,7 +67,7 @@ async def get_optional_user(
 
 
 async def get_admin_user(user: Annotated[User, Depends(get_current_user)]) -> User:
-    if user.profile.role != "admin":
+    if user.role != "admin":
         raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="需要管理员权限")
     return user