ADR 0001: Python toolchain

• Status: Accepted
• Date: 2026-11-11

Context

We need a modern, fast, reproducible Python setup that reviewers recognise.

Decision

Python >= 3.11, uv for env/deps/build, ruff (lint+format), mypy --strict on src/, pytest + pytest-cov + hypothesis, pre-commit. src-layout package, pyproject.toml only.

Consequences

Fast CI, single config file. uv is newer than pip/poetry, but widely adopted in 2025-26.