Durable, channel-agnostic code-keyed adjudication ledger (answered-state beyond inline threads)

• #151's own driving instance: on salix#100 the author dismissed with measured evidence across rounds; the round-9 dismissal was a top-level #issuecomment (issuecomment-5243600862), not an inline thread reply — invisible to an inline-thread scrape. #151's spec text itself says the match is "When a finding's code (or title) matches a prior round where the author replied with an explicit dismissal" — code-keyed, not thread-keyed.
• #98:44 already established the durable substrate: "The prior rounds are already on the PR and need no new store. Each round is submitted as a PullRequestReview … carrying its own code-review:findings-json … GET /pulls/{n}/reviews is already the durable history, for both the findings and the SHA each was judged against." The history is channel-agnostic and durable; what's missing is a disposition keyed to it.
• Strays / systemic problems have no inline thread. A maintainer who writes "the systemic caching observation is intentional" under the sticky has no inline comment to thread onto; the current anchor cannot record that dismissal at all.

The hard part is that a dismissal is a human decision, and the human's expression of it can land anywhere. Candidate approaches, roughly increasing in ambition:

1. Widen the scan. In addition to inline threads, read the channels #98 already gathers (top-level issue comments, review summaries) and the reviews API, and match any human message that references a finding's code or its 1-based index to that finding — feeding the same applyAnswered/seed machinery. Cheapest; catches the common "reply by code/index in the PR conversation" case. Risk: false matches on incidental mentions of a code.
2. A durable code-keyed adjudication ledger carried in the sticky's machine channel (a marker, like rounds), recording per-code disposition (answered / declined / policy-suppressed / accepted) and a link to where the human said so. The seed delivers it; post re-derives/updates it. Generalizes #164's nit-stickiness from "policy-suppressed nits" to "any adjudicated finding," and does not depend on re-finding the reply each round.
3. A dismissal convention the human opts into (e.g. a reply containing the finding's code), so the signal is unambiguous and channel-independent by construction — documented in the sticky's "how to consume/respond" contract (ties to #171's "read the schema/markers" push).

Whatever the shape, the invariant from the nit-floor work holds: adjudication state that is only remembered in one fragile place (an inline thread) is re-litigated whenever the human used a different place. Key it by code (else index/title, the existing answeredNoteKey contract) in a durable channel.