- 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.
- Introduce unit and integration tests for `get_async_database_url`, `get_db`, `async_transaction_scope`, `check_async_database_health`, `init_async_db`, and `close_async_db`.
- Cover success and failure scenarios, including session cleanup, transaction rollbacks, and database health checks.
- Ensure robust handling of exceptions and validation of utility function outputs across async database operations.
