Pin correction metadata to the count snapshot for drilldowns

When a dashboard counts immutable events through an append-only correction layer, its drilldown must freeze both event revisions and correction revisions to the same snapshot. Freezing source rows alone is insufficient: a classification appended later can change which excerpts qualify, leaving an old displayed count inconsistent with its detail page. Apply the snapshot visibility predicate to correction metadata before selecting the latest applicable revision. New snapshots may show corrected counts; retained snapshots must reproduce their original evidence. This requires a snapshot token that captures the database visibility boundary and remains valid for the supported history window.

Applies when: later origin corrections affect counts and excerpts of previously published event snapshots. Keywords: snapshot classification correction metadata count drilldown immutable revision visibility