[governance] Enforce the ADR merge prohibition on the GitHub side — prose did not propagate; two seats merged docs/adr/** PRs within an hour of the ruling #6785

Filed at the maintainer's direction (2026-08-08, Claude Code session of the devx PM seat): 「两个 ADR 都追认,GitHub 侧的 ruleset 门禁开卡去做」.

The ruling to enforce

#6741, maintainer, verbatim: 「adr 只能由维护者自己确认,人工合并,ai 不得擅自合并。」

Why prose enforcement is measured-insufficient

The ruling was filed at 13:52Z on 2026-08-08. Within the following hour, two different AI-operated seats merged docs/adr/** PRs:

The maintainer confirms neither was them; both were retroactively ratified on #6741 — ratification covered those two merges only and explicitly declined to set precedent. The mechanism failure is structural: a ruling written into an issue (or into one lane's SKILL.md) does not reach sessions that never read that issue. #6732 was merged while in draft state, which also demonstrates that parking a PR as draft is not a reliable barrier. The repo's own doctrine — declared = enforced — applies to governance exactly as it applies to metadata.

What to build

Machine enforcement: a PR whose diff touches docs/adr/** must not be mergeable without the maintainer's explicit approval. Two complementary halves; the split matters because only one half is self-serve:

Half 1 — in-repo, a dev can land it

1. .github/CODEOWNERS entry routing docs/adr/ to the maintainer (@hotlong), so review is requested automatically and a code-owner-review requirement has something to bind to.
2. A CI check (workflow + script, in the family of check-changeset-presence in objectui#3769) that:
   • runs on every PR with no path filter on the trigger — the script reads the diff and decides; a filtered-out required check never reports and hangs the merge queue for the ruleset timeout (objectui#3523's lesson, restated in 黑洞型数据库端点：每个查询挂 30 秒，然后报一句指向错误方向的 "the pool is probably full" #3769);
   • subscribes to merge_group as well, so a queued build reports rather than stalling;
   • passes when the diff does not touch docs/adr/**;
   • when the diff does touch it, passes only if the PR carries an APPROVED review from the maintainer's own account — a bot-identity approval must not satisfy it (the shared-identity problem is the root cause here; an approval from os-*/claude identities is exactly what must not count);
   • fails loud on missing inputs (diff unavailable, review list unfetchable) — never a silent exit 0, per the check:react-declaration-parity 是唯一没接进任何 workflow 的源码审计门禁,且无 MANIFEST 时静默 skip 退出 0 —— 它现在永远不可能红 #4690 anti-pattern and objectstack#4928 filter contract;
   • carries a self-test, and the PR proves the red path with direction predicted before each ablation (a docs/adr/** diff with no approval → RED; same diff plus maintainer approval → GREEN; non-ADR diff → GREEN without lookups).

Half 2 — repo settings, only the maintainer can flip it

Document, in the PR body, the exact ruleset/branch-protection changes for the maintainer to apply by hand: require code-owner review on docs/adr/** paths (binding to the CODEOWNERS entry), and add the new check to required status checks. ⛔ The dev must not attempt to modify repository settings via API even if the token permits it — the entire point of this card is that governance actions belong to the maintainer; the deliverable is the button-by-button instruction, not the pressed button.

Scope guards

• ⛔ No edits under docs/adr/** itself.
• ⛔ This gate governs merging, not authoring — drafting ADR PRs remains permitted to all seats; only the merge is reserved.
• The check must not block the emergency lever the maintainer already has: their own approval + merge is the intended green path, zero extra friction for them.
• Account-identity detail to verify rather than assume: the maintainer's GitHub login for CODEOWNERS/approval-matching purposes (the seat's records say hotlong; confirm against the repo's admin/collaborator list).

Acceptance

• Replay evidence: run the check against PRs docs(adr): ADR-0048 addendum — publish-time / marketplace namespace exclusivity contract #6671 and docs(adr),chore(devx): reconstruct ADR-0079 + make every cited ADR number resolve #6732 as historical inputs — both must go RED under the new rule (no maintainer approval was present on either).
• Self-referential smoke: the gate runs green on its own PR (which touches .github/ and scripts/, not docs/adr/**).

Related: #6741 (the ruling and both violation records), #6634/PR #6732, #1825/PR #6671, objectui#3769 (the presence-gate pattern this borrows), #6170 (the sibling prohibition on release actions — worth checking whether the same mechanism can carry it later, but ⛔ out of scope for this card).