feat: Enhance models and README with additional features and improvements

- Updated README to include KodBox in project vision.
- Added model descriptions for clarity in Download, File, Folder, Group, Node, Order, Policy, Redeem, Report, Request, Response, Setting, Share, SourceLink, StoragePack, Tag, Task, User, and WebDAV.
- Changed optional fields from Optional[...] to the new union type syntax (e.g., str | None).
- Improved foreign key references in models for consistency.
- Refactored relationships in models to use singular forms where appropriate.
- Updated login service to reflect changes in request model types.

models/download.py

@@ -11,7 +11,8 @@ class DownloadBase(SQLModelBase):
     pass
 
 class Download(DownloadBase, UUIDTableBase, table=True):
-    __tablename__ = 'downloads'
+    """离线下载任务模型"""
+
     __table_args__ = (
         UniqueConstraint("node_id", "g_id", name="uq_download_node_gid"),
     )
@@ -21,18 +22,18 @@ class Download(DownloadBase, UUIDTableBase, table=True):
     source: str = Field(description="来源URL或标识")
     total_size: int = Field(default=0, sa_column_kwargs={"server_default": "0"}, description="总大小（字节）")
     downloaded_size: int = Field(default=0, sa_column_kwargs={"server_default": "0"}, description="已下载大小（字节）")
-    g_id: Optional[str] = Field(default=None, index=True, description="Aria2 GID")
+    g_id: str | None = Field(default=None, index=True, description="Aria2 GID")
     speed: int = Field(default=0, sa_column_kwargs={"server_default": "0"}, description="下载速度 (bytes/s)")
-    parent: Optional[str] = Field(default=None, description="父任务标识")
-    attrs: Optional[str] = Field(default=None, description="额外属性 (JSON格式)")
+    parent: str | None = Field(default=None, description="父任务标识")
+    attrs: str | None = Field(default=None, description="额外属性 (JSON格式)")
     # attrs 示例: {"gid":"65c5faf38374cc63","status":"removed","totalLength":"0","completedLength":"0","uploadLength":"0","bitfield":"","downloadSpeed":"0","uploadSpeed":"0","infoHash":"ca159db2b1e78f6e95fd972be72251f967f639d4","numSeeders":"0","seeder":"","pieceLength":"16384","numPieces":"0","connections":"0","errorCode":"31","errorMessage":"","followedBy":null,"belongsTo":"","dir":"/data/ccaaDown/aria2/7a208304-9126-46d2-ba47-a6959f236a07","files":[{"index":"1","path":"[METADATA]zh-cn_windows_11_consumer_editions_version_21h2_updated_aug_2022_x64_dvd_a29983d5.iso","length":"0","completedLength":"0","selected":"true","uris":[]}],"bittorrent":{"announceList":[["udp://tracker.opentrackr.org:1337/announce"],["udp://9.rarbg.com:2810/announce"],["udp://tracker.openbittorrent.com:6969/announce"],["https://opentracker.i2p.rocks:443/announce"],["http://tracker.openbittorrent.com:80/announce"],["udp://open.stealth.si:80/announce"],["udp://tracker.torrent.eu.org:451/announce"],["udp://exodus.desync.com:6969/announce"],["udp://tracker.tiny-vps.com:6969/announce"],["udp://tracker.pomf.se:80/announce"],["udp://tracker.moeking.me:6969/announce"],["udp://tracker.dler.org:6969/announce"],["udp://open.demonii.com:1337/announce"],["udp://explodie.org:6969/announce"],["udp://chouchou.top:8080/announce"],["udp://bt.oiyo.tk:6969/announce"],["https://tracker.nanoha.org:443/announce"],["https://tracker.lilithraws.org:443/announce"],["http://tracker3.ctix.cn:8080/announce"],["http://tracker.nucozer-tracker.ml:2710/announce"]],"comment":"","creationDate":0,"mode":"","info":{"name":""}}}
-    error: Optional[str] = Field(default=None, description="错误信息")
+    error: str | None = Field(default=None, description="错误信息")
     dst: str = Field(description="目标存储路径")
     
     # 外键
-    user_id: int = Field(foreign_key="users.id", index=True, description="所属用户ID")
-    task_id: Optional[int] = Field(default=None, foreign_key="tasks.id", index=True, description="关联的任务ID")
-    node_id: int = Field(foreign_key="nodes.id", index=True, description="执行下载的节点ID")
+    user_id: int = Field(foreign_key="user.id", index=True, description="所属用户ID")
+    task_id: int | None = Field(default=None, foreign_key="task.id", index=True, description="关联的任务ID")
+    node_id: int = Field(foreign_key="node.id", index=True, description="执行下载的节点ID")
     
     # 关系
     user: "User" = Relationship(back_populates="downloads")