bug(unic-archon-dlc): an unverified finding has no way out of the ledger #662

Problem

#482 adds the verdict unverified to unic-dlc-pr-review. In reconcile, a prior unverified finding with no match is fixed or unverified again, never retired. So an unverified finding leaves the summary's unverified list and its count only when its file changes between two recorded heads. Two kinds of finding never get there:

• A scoped finding, whose file is pull request, work item or repository. It has no path, so it is never fixed. It has no thread either, so the "a person closes it" of the ticket's decision 6 has nothing to act on.
• An anchored unverified finding whose thread a person resolved after checking it by hand. prep reads no thread status into prior_verdict, so resolving the thread changes nothing in the ledger.

The reply on an unverified thread asks the author to resolve the thread if the finding is gone. Doing so has no effect on what the Box reports, and the unverified count grows over the life of a pull request.

Found by review round 1 of PR #661, which is out of that ticket's scope.

Acceptance criteria

• The Box doc apps/claude-code/unic-archon-dlc/docs/boxes/unic-dlc-pr-review.md states how an unverified finding leaves the ledger, for an anchored finding and for a scoped one.
• An anchored unverified finding whose thread a person resolved, and which the review does not report again, is no longer counted as unverified in the next iteration.
• A scoped unverified finding has a way out that a person can take on the pull request, and the summary says what it is.
• A resolved thread whose finding the review reports again is still reopened, as decision 7 of bug(unic-archon-dlc): reconcile marks a finding fixed when the next review omits it, and post resolves the thread #482 requires.