feat: add models for physical files, policies, and user management

- Implement PhysicalFile model to manage physical file references and reference counting.
- Create Policy model with associated options and group links for storage policies.
- Introduce Redeem and Report models for handling redeem codes and reports.
- Add Settings model for site configuration and user settings management.
- Develop Share model for sharing objects with unique codes and associated metadata.
- Implement SourceLink model for managing download links associated with objects.
- Create StoragePack model for managing user storage packages.
- Add Tag model for user-defined tags with manual and automatic types.
- Implement Task model for managing background tasks with status tracking.
- Develop User model with comprehensive user management features including authentication.
- Introduce UserAuthn model for managing WebAuthn credentials.
- Create WebDAV model for managing WebDAV accounts associated with users.

sqlmodels/task.py

@@ -0,0 +1,153 @@
+from enum import StrEnum
+from typing import TYPE_CHECKING
+from uuid import UUID
+from datetime import datetime
+
+from sqlmodel import Field, Relationship, CheckConstraint, Index
+
+from .base import SQLModelBase
+from .mixin import TableBaseMixin
+
+if TYPE_CHECKING:
+    from .download import Download
+    from .user import User
+
+
+class TaskStatus(StrEnum):
+    """任务状态枚举"""
+    QUEUED = "queued"
+    """排队中"""
+    RUNNING = "running"
+    """处理中"""
+    COMPLETED = "completed"
+    """已完成"""
+    ERROR = "error"
+    """错误"""
+
+
+class TaskType(StrEnum):
+    """任务类型枚举"""
+    # [TODO] 补充具体任务类型
+    pass
+
+
+# ==================== DTO 模型 ====================
+
+
+class TaskSummaryBase(SQLModelBase):
+    """任务摘要基础字段"""
+
+    id: int
+    """任务ID"""
+
+    type: int
+    """任务类型"""
+
+    status: TaskStatus
+    """任务状态"""
+
+    progress: int
+    """进度（0-100）"""
+
+    error: str | None
+    """错误信息"""
+
+    user_id: UUID
+    """用户UUID"""
+
+    created_at: datetime
+    """创建时间"""
+
+    updated_at: datetime
+    """更新时间"""
+
+
+class TaskSummary(TaskSummaryBase):
+    """任务摘要，用于管理员列表展示"""
+
+    username: str | None
+    """用户名"""
+
+    @classmethod
+    def from_task(cls, task: "Task", user: "User | None") -> "TaskSummary":
+        """从 Task ORM 对象构建"""
+        return cls(
+            **TaskSummaryBase.model_validate(task, from_attributes=True).model_dump(),
+            username=user.email if user else None,
+        )
+
+
+# ==================== 数据库模型 ====================
+
+
+class TaskPropsBase(SQLModelBase):
+    """任务属性基础模型"""
+
+    source_path: str | None = None
+    """源路径"""
+
+    dest_path: str | None = None
+    """目标路径"""
+
+    file_ids: str | None = None
+    """文件ID列表（逗号分隔）"""
+
+    # [TODO] 根据业务需求补充更多字段
+
+
+class TaskProps(TaskPropsBase, TableBaseMixin):
+    """任务属性模型（与Task一对一关联）"""
+
+    task_id: int = Field(
+        foreign_key="task.id",
+        primary_key=True,
+        ondelete="CASCADE"
+    )
+    """关联的任务ID"""
+
+    # 反向关系
+    task: "Task" = Relationship(back_populates="props")
+    """关联的任务"""
+
+
+class Task(SQLModelBase, TableBaseMixin):
+    """任务模型"""
+
+    __table_args__ = (
+        CheckConstraint("progress BETWEEN 0 AND 100", name="ck_task_progress_range"),
+        Index("ix_task_status", "status"),
+        Index("ix_task_user_status", "user_id", "status"),
+    )
+
+    status: TaskStatus = Field(default=TaskStatus.QUEUED)
+    """任务状态"""
+
+    type: int = Field(default=0)
+    """任务类型 [TODO] 待定义枚举"""
+
+    progress: int = Field(default=0, ge=0, le=100)
+    """任务进度（0-100）"""
+
+    error: str | None = Field(default=None)
+    """错误信息"""
+
+    # 外键
+    user_id: UUID = Field(
+        foreign_key="user.id",
+        index=True,
+        ondelete="CASCADE"
+    )
+    """所属用户UUID"""
+
+    # 关系
+    props: TaskProps | None = Relationship(
+        back_populates="task",
+        sa_relationship_kwargs={"uselist": False, "cascade": "all, delete-orphan"},
+    )
+    """任务属性"""
+
+    user: "User" = Relationship(back_populates="tasks")
+    """所属用户"""
+
+    downloads: list["Download"] = Relationship(back_populates="task")
+    """关联的下载任务"""