- Reformat argument list for better readability and consistency.
- Update indentation and braces to align with standard conventions.
No functional changes introduced.
- Extracted checks (clippy, doc, fmt, and toml-fmt) into modularized Nix files under `nix/checks`.
- Updated `flake.nix` to import checks from the new modularized structure.
- Improved clarity and maintainability by separating concerns for each check.
