Empty — this is infrastructure only (#957). No data migration is required
at this time; the runner, version comparison, per-type dispatch, and version
stamping are all in place so a future migration plugs in as one frozen entry
here (append in version order — the planner sorts defensively regardless).
The ordered list of world migrations.
Empty — this is infrastructure only (#957). No data migration is required at this time; the runner, version comparison, per-type dispatch, and version stamping are all in place so a future migration plugs in as one frozen entry here (append in version order — the planner sorts defensively regardless).