02 — The template

copier.yml defines the questions; template/ is what gets rendered. Files ending in .jinja are rendered, everything else is copied as is. The template uses [[ … ]] and [% … %] as Jinja delimiters, so GitHub Actions expressions (${{ … }}) pass through untouched.

Who owns what

Owned by the template (updated by copier update)	Owned by the project (rendered once, never touched again)
docs/standards/*.md (the generic rules)	docs/standards/project/ (project rules)
.pre-commit-config.yaml, .github/ (workflows, scripts, PR template), mkdocs.yml (project pages need no nav edit)	README.md (but its badge and gates blocks are generated, see 08)
pyproject.toml tool configuration, standards.toml	src/, tests/, tools/, scripts/, notebooks/
AGENTS.md, CLAUDE.md, SECURITY.md, LICENSE	planning/SPEC.md, planning/ROADMAP.md, ADR 0001, planning/standards-feedback.md
	.importlinter (the project's own layers)

Template-owned files can still be edited by a project. copier update merges both sides with a 3-way merge, and shows a real conflict when both sides changed the same lines. Generic rules, however, are changed only upstream (STD-1).

Updating

uvx copier update --trust                 # to the latest release
uvx copier update --trust --vcs-ref v0.2.0  # to a given release

Do it on a build/standards-vX.Y.Z branch, then run uv lock (the post-render tasks only run on the first render, so the update never conflicts in uv.lock) and open a PR. The answers and the template release are recorded in .copier-answers.yml. pyproject.toml pins the standards CLI to the same commit as the template, so documents and checks always come from one release.

Updating from v0.4.2 or earlier, once. Those versions ran their post-render tasks inside Copier's replay of the old version, so the first update to a later version reports uv.lock as deleted. Restore it and re-lock:

git checkout HEAD -- uv.lock && uv lock