0008. The driver is pure stdlib, Python ≥ 3.11

Context

The driver is rendered into every instance and runs on maintainers' machines, in CI and in sandboxes next to whatever toolchain the target project uses. Third-party dependencies would have to be installed and kept compatible in every one of those environments.

Decision

The driver uses the Python standard library only: dependencies = [] and requires-python = ">=3.11" in template/pyproject.toml.jinja, from the first commit (3ca179a, 2026-06-04). External tools (git, gh, the model CLIs, Copier) are invoked as subprocesses and checked by pdca doctor.

Consequences

An instance needs only Python and the CLIs it already uses. Parsing TOML uses tomllib (hence 3.11). Anything a library would give — schema validation, structured config, typed records — is written by hand; migration steps 1 and 3 keep to this when they add records and output schemas. The docs site renderer under docs/publishing/ is outside the driver and may use its own pinned packages.