quality-checks.yml implements the contract of ADR-0005: inputs for the
languages, the working directory and one pinned version per tool; ruff,
mypy --strict, shellcheck and shfmt installed from PyPI into a venv; every
tool runs and any failure fails the job; a language without files is skipped
with a notice. Offline tests run the shell steps with stub tools. Verified
live from another organisation with clean files, a seeded failure and an
empty language.
Task: MIL-003#3
