- 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.
- **Security Headers:** Add tests for HSTS in production, CSP in strict mode, and root endpoint response types.
- **Permissions:** Introduce tests for critical security paths, including superuser bypass and edge case scenarios.
- **CRUD Testing Enhancements:** Cover error scenarios for soft deletes, restores, and eager loading with SQLAlchemy options.
- **Organization Routes:** Validate user organization endpoints for memberships, details, and member listings.
- Add defensive code comments with `# pragma: no cover` for unreachable code sections.
- Introduced new unit tests for session CRUD operations, including `update_refresh_token`, `cleanup_expired`, and multi-user session handling.
- Added comprehensive tests for `CRUDBase` methods, covering edge cases, error handling, and UUID validation.
- Reduced default test session creation from 5 to 2 for performance optimization.
- Enhanced pagination, filtering, and sorting validations in `get_multi_with_total`.
- Improved error handling with descriptive assertions for database exceptions.
- Introduced tests for eager-loaded relationships in user sessions for comprehensive coverage.
- Deleted `test_crud_base.py`, `test_crud_error_paths.py`, and `test_organization_async.py` due to the removal of corresponding deprecated CRUD implementations.
- Improved codebase maintainability and reduced test suite noise by eliminating obsolete test files.
- Deleted outdated backend test cases (`test_auth.py`, `test_rate_limiting.py`, `test_users.py`) to clean up deprecated test structure.
- These tests are now redundant with newer async test implementations and improved coverage.
- Refactored all `password reset` and `auth dependency` tests to utilize async patterns for compatibility with async database sessions.
- Enhanced test fixtures with `pytest-asyncio` to support asynchronous database operations.
- Improved user handling with async context management for `test_user` and `async_mock_user`.
- Introduced `await` syntax for route calls, token generation, and database transactions in test cases.
- Added security headers middleware to enforce best practices (e.g., XSS and clickjacking prevention, CSP, HSTS in production).
- Updated `User` model schema: refined field constraints and switched `preferences` to `JSONB` for PostgreSQL compatibility.
- Introduced tests to validate security headers across endpoints and error responses.
- Ensured headers like `X-Frame-Options`, `X-Content-Type-Options`, and `Permissions-Policy` are correctly configured.
