QEP-5 adoption: execution checklist

[mmcky]

Execution checklist for QEP-5, Code of AI Use (#13). The QEP states the obligations; this issue carries the rollout, per the convention that a QEP's Adoption section holds obligations and the execution detail lives in a tracking issue. Blocked on #13's acceptance; several items can be drafted now.

At landing (same squash as #13)

• Apply the Amendments to QEP-2 section as a file edit: the good first issue row's When to use cell gains the norm-5 reservation. QEP-2 is unversioned on main, so this is its first substantive amendment: version: 1 in the frontmatter and a Version row in the header table. The yml appendix does not change.
• Close QEP idea: Contributor registry, AI-use attestation, and a PR gate #12 with a pointer to the retained registry and gate design in QuantEcon/infrastructure#5 and the revival trigger: GitHub's native volume controls proving insufficient.

The three visibility channels

• Pull-request template and CONTRIBUTING default in QuantEcon/.github. A PULL_REQUEST_TEMPLATE.md with the checkbox pair as worded in the QEP, and a default CONTRIBUTING.md documenting the Assisted-by: trailer and the tool-emitted Co-Authored-By: form. Checked 2026-09-11: none of QuantEcon.py, lecture-python.myst, lecture-python-intro.myst, or lecture-python-advanced.myst has a pull-request template, so the org default reaches all four. QuantEcon.py has its own CONTRIBUTING.md, so the org default does not reach it; edit that file (and the rendered guide it points to) directly.
• The Code in brief in AGENTS.md, stamped and drift-checked by the CLI: QuantEcon/cli#50. QuantEcon.py first, then the lectures profile.
• The disclosure-ask comment on external pull requests: Disclosure ask on external pull requests: a comment-only workflow under QEP-5 meta#385. Reusable workflow in QuantEcon/.github, caller stamped per repository, pilot on QuantEcon.py.
• Structured issue templates link to the policy (the same text agents echo back verbatim).

Follow-on amendments to other QEPs

• QEP-1: codify the in-document appendix. QEP-5 is the second QEP to carry a normative appendix (QEP-2's yml was the first), which was the agreed trigger for generalising the convention. Proposed shape, to be discussed on the amendment PR: an optional, normative block bounded by <!-- qep-appendix: <id> --> and <!-- /qep-appendix -->, extractable as a substring with no markdown parsing; any change to it is a substantive bump; the QEP names the tool that consumes it; everything stays in the one markdown file, with a fenced block for data and a GitHub alert for prose. Decide whether QEP-2's co-located yml migrates into a fenced block or stays as the one file-form exception. Lands after QEP-1 v3: stamp from v0; drop the decision deadline; generate the index #23 (QEP-1 v3), so this is v4.

Field testing (per #14)

• Norms 4, 5 (the good first issue rule), and 6, the organisation-automation carve-out, and the scope beyond pull requests are untested. Record the first instance of each here as it happens.
• After the ask comment has run for a month: how many external pull requests received it, how many answered, how many added the trailer.