Contributing

1. Fork / branch from main
2. Install: pip install -e ".[testing,linting,docs]"
3. Run tests: python -m pytest or tox
4. Run hooks: pre-commit run --all-files
5. Add a towncrier news fragment under news/ for user-visible changes
6. Open a pull request

Template changes that affect all pure-Python children must land in ateco first (AR-036).