- Introduced `pyproject.toml` to centralize backend tool configurations (e.g., Ruff, mypy, coverage, pytest).
- Replaced Black, isort, and Flake8 with Ruff for linting, formatting, and import sorting.
- Updated `requirements.txt` to include Ruff and remove replaced tools.
- Added `Makefile` to streamline development workflows with commands for linting, formatting, type-checking, testing, and cleanup.
- **Configurations:** Test minimum `SECRET_KEY` length validation to prevent weak JWT signing keys. Validate proper handling of secure defaults.
- **Permissions:** Add tests for inactive user blocking, API access control, and superuser privilege escalation across organizational roles.
- **Authentication:** Test logout safety, session revocation, token replay prevention, and defense against JWT algorithm confusion attacks.
- Include `# pragma: no cover` for unreachable defensive code in security-sensitive areas.
