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/report.py

@@ -1,20 +1,19 @@
 
-from typing import Optional, TYPE_CHECKING
-from sqlmodel import Field, Relationship, Column, func, DateTime
+from typing import TYPE_CHECKING
+from sqlmodel import Field, Relationship
 from .base import TableBase
-from datetime import datetime
 
 if TYPE_CHECKING:
     from .share import Share
 
 class Report(TableBase, table=True):
-    __tablename__ = 'reports'
+    """举报模型"""
 
     reason: int = Field(description="举报原因代码")
-    description: Optional[str] = Field(default=None, max_length=255, description="补充描述")
+    description: str | None = Field(default=None, max_length=255, description="补充描述")
     
     # 外键
-    share_id: int = Field(foreign_key="shares.id", index=True, description="被举报的分享ID")
+    share_id: int = Field(foreign_key="share.id", index=True, description="被举报的分享ID")
     
     # 关系
     share: "Share" = Relationship(back_populates="reports")