Toolchain and contribution policies

Python 3.10 is the supported floor; CI tests 3.10–3.14 on Linux. Development uses Python 3.12 and Poetry with the committed lock. No distro-system-Python compatibility is claimed.

The floor may rise only under ADR-0004: after upstream end-of-life, announced one release ahead and recorded as a breaking change. Versions advance one step at a time; the maintainer opens releases. See stability policy, contribution rules and governance.