selection_evidence is continue-on-error on both the job and its comparison step,
so it can never fail a PR -- it downloads the shard reports, compares selection
against the full results and uploads a review artifact. But a caller's
`needs: test` waits for every job in the called workflow, so living inside
unit-tests.yml it held verify for ~36s after the last shard finished.
It moves to its own reusable workflow called as a sibling, so it still runs on
every PR and still uploads its artifact, but verify no longer waits for it. It is
deliberately absent from verify's needs, and a contract test pins both that and
its advisory status so it cannot drift back onto the critical path.
Measured on a recent run: the shards finished, then selection_evidence ran 36s,
then verify 3s. Only the last of those gates anything.
Neil
2ea3fb1d46