# Rollback / forward policy

This STEP does **not** apply Alembic 0002 to the live VM121 database.

Before the core boundary, any failure removes the newly added source file:

`/opt/wg-access/backend/alembic/versions/0002_live_drift_bridge.py`

and verifies that VM121 Machine Git is back at the exact pre-step baseline.
The encrypted DB backup is deliberately retained.

After both temporary-database fixtures pass, the source file is considered the
completed core change and Machine Git is closed/published. A later publication
failure must use continuation; do not delete or re-run the proven migration
fixtures automatically.

`0002_live_drift_bridge` intentionally refuses destructive Alembic downgrade.
When P2.1C later applies it to live, rollback is restore from the encrypted
pre-migration backup, not object-dropping downgrade.