# P23A rollback / continuation

Before the P23A core boundary, rollback is limited to deleting
`/opt/wg-access/backend/alembic/versions/0003_domain_v2_schema.py` **only when
its SHA256 exactly matches the P23A candidate**. The live DB is never mutated by
P23A, so no database rollback exists in this STEP.

The core boundary is reached after both isolated migration fixtures PASS, the
candidate migration is atomically installed, its hash/compile check passes,
and independent checks prove the live DB is still `0002_live_drift_bridge`
with zero Domain V2 tables and a healthy backend.

After that boundary, Machine Git close/report/publication failures are
continuation work. Do not delete or recreate the tested migration source merely
to repair publication.