- Removed the `available_nodes` field from the GroupOptions model in `group.py`.
- Updated imports in `pwd.py` by removing unused imports.
- Added a comprehensive roadmap document outlining the development stages and features for DiskNext Server.
- Created a detailed README for the models directory, documenting the database models and their relationships.
- 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.
