[finding] A comment-only review handoff is invisible to the review gate AND to every patrol — two ready-flipped PRs sat unreviewed until the maintainer noticed by hand #11994

Filed as recording; measured 2026-08-25 while repairing the state (verdicts now on #11374 / #11794).

What happened

The domain:engine seat delivered two PRs — #11699 (delivering #11374 route A) and #11876 (delivering #11794) — flipped both to ready, and wrote on each a handoff comment: "Ready for triage review — ⛔ deliberately NOT enqueued … the maintainer directed that this go to triage review". No needs:contract-review label was hung on any of the four carriers (either PR, either card). The label-driven review cron (which lists open cards by that single label) therefore never saw them; both sat ready-and-unreviewed for ~5–13 hours until the maintainer noticed the labels had never changed and reported it in chat. One of the two (#11876) had been dispatched below CONTRACT_REVIEW_TIER by explicit quota ruling with the review chain as the named compensation — so the missing link was the exact link the ruling depended on.

The mechanism gap, precisely

• The review gate's inbox is list_issues(labels: [needs:contract-review], state: open). A handoff that exists only as prose in a PR comment has no representation in that query.
• H31 (contract-review dual-carrier split) detects a label present on ONE carrier and missing from the other. Zero-on-both is indistinguishable from "no review owed" — by construction, since the label is the only machine-readable claim that a review IS owed.
• No patrol reads handoff comments. The failure is silent on every existing scan: not a half-state, not a split, not queue rot.

Not claimed

• ⛔ Not a claim the review chain's label protocol is wrong — the label IS the right bus; the defect is that nothing catches a seat that writes the prose and skips the label.
• ⛔ Not measured: how often this shape occurs. This is n=2 from one seat in one evening (both repaired same-day).

Possible directions (triage, not a recommendation)

• A patrol heuristic: an OPEN, READY (non-draft) PR by a bot identity whose body/comments contain a "review" handoff phrase but which carries none of the review-chain labels ⇒ flag. Phrase-matching prose is brittle; the value is that this exact shape is loud ("Ready for triage review" is a fixed formula in seat handoff comments).
• A protocol row in the state-machine doc: "the handoff IS the label — a handoff comment without the same-stroke label write is a null handoff", plus read-back discipline quoted at the seat that skipped it. Cheap, already half-stated in the review-chain bullets; makes the defect chargeable to the seat rather than invisible.
• Both, or nothing (n=2, same-day repair, and the dispatching seat has now been named on both cards).

Generated by Claude Code