1.8.0

Changed

• migrate project metadata from deprecated [tool.poetry] keys to PEP 621 [project]
• make production dependency constraints more flexible (charset_normalizer, tomli extra)
• refresh development, testing, and linting dependency versions
• add root Makefile with common development tasks (install, test-*, lint, format, docs, clean)
• expand tox/CI Python matrix to include Python 3.14