Edits fork, never overwrite

Publishing a change creates a new version chained to the original. Every version that ever ran is still there to inspect, with field-level change history recorded on top.

In-flight work is pinned

A request takes a full snapshot of its template at submission and reads only that snapshot from then on. Publish version seven mid-afternoon; the open version-six requests finish exactly as version six defined.

Any version can come back

The full lineage is queryable, and re-publishing a prior version makes it current again, so a rollback is really a fast-forward to a known-good state.

Migration is a decision, not an accident

When open requests should move to the new rules, forced migration moves them explicitly, reports how many moved, and audits each one with its from-and-to versions.