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/source_link.py

@@ -0,0 +1,37 @@
+
+from typing import TYPE_CHECKING
+from uuid import UUID
+
+from sqlmodel import Field, Relationship, Index
+
+from .base import SQLModelBase
+from .mixin import TableBaseMixin
+
+if TYPE_CHECKING:
+    from .object import Object
+
+
+class SourceLink(SQLModelBase, TableBaseMixin):
+    """链接模型"""
+
+    __table_args__ = (
+        Index("ix_sourcelink_object_name", "object_id", "name"),
+    )
+
+    name: str = Field(max_length=255)
+    """链接名称"""
+
+    downloads: int = Field(default=0, sa_column_kwargs={"server_default": "0"})
+    """通过此链接的下载次数"""
+
+    # 外键
+    object_id: UUID = Field(
+        foreign_key="object.id",
+        index=True,
+        ondelete="CASCADE"
+    )
+    """关联的对象UUID（必须是文件类型）"""
+
+    # 关系
+    object: "Object" = Relationship(back_populates="source_links")
+    """关联的对象"""