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/models.py

@@ -8,6 +8,7 @@ from sqlalchemy import (
     DateTime,
     ForeignKey,
     Index,
+    Integer,
     Numeric,
     SmallInteger,
     Text,
@@ -32,42 +33,28 @@ class TimestampMixin:
 
 class User(Base, TimestampMixin):
     __tablename__ = "users"
+    __table_args__ = (
+        CheckConstraint("length(trim(username)) >= 2", name="ck_users_username_length"),
+        CheckConstraint("role IN ('user', 'admin')", name="ck_users_role"),
+    )
 
     id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
     email: Mapped[str] = mapped_column(Text, unique=True, nullable=False)
     password_hash: Mapped[str] = mapped_column(Text, nullable=False)
     email_verified_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
 
-    profile: Mapped["Profile"] = relationship(
-        back_populates="user", cascade="all, delete-orphan", uselist=False, lazy="raise"
-    )
-    clouds: Mapped[list["Cloud"]] = relationship(back_populates="user", lazy="raise")
-
-
-class Profile(Base):
-    __tablename__ = "profiles"
-    __table_args__ = (
-        CheckConstraint("length(trim(username)) >= 2", name="ck_profiles_username_length"),
-        CheckConstraint("role IN ('user', 'admin')", name="ck_profiles_role"),
-    )
-
-    id: Mapped[uuid.UUID] = mapped_column(
-        Uuid, ForeignKey("users.id", ondelete="CASCADE"), primary_key=True
-    )
     username: Mapped[str] = mapped_column(Text, unique=True, nullable=False)
     avatar_path: Mapped[str | None] = mapped_column(Text)
     role: Mapped[str] = mapped_column(Text, nullable=False, default="user", server_default="user")
     is_disabled: Mapped[bool] = mapped_column(
         Boolean, nullable=False, default=False, server_default=text("false")
     )
-    created_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), server_default=func.now(), nullable=False
-    )
-    updated_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
-    )
 
-    user: Mapped[User] = relationship(back_populates="profile", lazy="raise")
+    cloud_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0, server_default="0")
+    public_cloud_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0, server_default="0")
+    collection_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0, server_default="0")
+
+    clouds: Mapped[list["Cloud"]] = relationship(back_populates="user", lazy="raise")
 
 
 class RefreshSession(Base):
@@ -163,28 +150,7 @@ class Cloud(Base, TimestampMixin):
         ),
         Index("ix_clouds_user_id", "user_id"),
         Index("ix_clouds_cloud_type_id", "cloud_type_id"),
-        Index("ix_clouds_user_captured", "user_id", text("captured_at DESC"), text("created_at DESC")),
         Index("ix_clouds_status_created", "status", text("created_at DESC")),
-        Index(
-            "ix_clouds_public_gallery",
-            text("created_at DESC"),
-            text("id DESC"),
-            postgresql_where=text("status = 'approved' AND is_hidden = false"),
-        ),
-        Index(
-            "ix_clouds_public_map",
-            "captured_at",
-            postgresql_where=text(
-                "status = 'approved' AND is_hidden = false "
-                "AND latitude IS NOT NULL AND longitude IS NOT NULL"
-            ),
-        ),
-        Index(
-            "ix_clouds_public_type",
-            "cloud_type_id",
-            text("captured_at DESC"),
-            postgresql_where=text("status = 'approved' AND is_hidden = false"),
-        ),
     )
 
     id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
@@ -206,6 +172,7 @@ class Cloud(Base, TimestampMixin):
     is_hidden: Mapped[bool] = mapped_column(
         Boolean, nullable=False, default=False, server_default=text("false")
     )
+    favorite_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0, server_default="0")
 
     user: Mapped[User] = relationship(back_populates="clouds", lazy="raise")
     cloud_type: Mapped[CloudType | None] = relationship(lazy="raise")
@@ -239,19 +206,11 @@ class UserCollection(Base):
 
 
 class CloudFavorite(Base):
-    """用户对照片的点赞/收藏记录。"""
-
     __tablename__ = "cloud_favorites"
     __table_args__ = (
         UniqueConstraint("user_id", "cloud_id", name="uq_cloud_favorites_user_cloud"),
         Index("ix_cloud_favorites_user_id", "user_id"),
         Index("ix_cloud_favorites_cloud_id", "cloud_id"),
-        Index(
-            "ix_cloud_favorites_user_created",
-            "user_id",
-            text("created_at DESC"),
-            text("id DESC"),
-        ),
     )
 
     id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)