Workflow reverts must preserve historical readers

When reverting a workflow while retaining its stored decision records, separate enforcement code from historical readers. Removing the workflow's pending-state machinery can be intentional while deleting the same format's aggregate-history predicate silently changes counts. Scope reviews should trace retained formats into both history displays and aggregate predicates, and cover records that exist only in the retired format. This applies when old records remain meaningful; an explicitly approved rewrite or history removal changes the contract.

Evidence/example — 2026-09-13: a delegated static diff review identified an aggregate predicate removal that excluded previously reviewed, currently successful records when their only review history used the retained format. The inference follows the query conditions; no live-data occurrence or runtime reproduction was established.