Harden migration preflight and startup adoption checks

README.md

@@ -61,12 +61,18 @@ The material-group preflight reports one of four states:
 - `APPLY`: migration history is complete and the group schema is absent; run
   `prisma migrate deploy` normally.
 - `ADOPT`: prior migrations are tracked and the database exactly matches the
-  intended group schema. After reviewing the verified backup, explicitly run
+  intended schema of one or more unrecorded committed migrations. This includes
+  recovery from P3018 when an already schema-pushed table or column exists.
+  After reviewing the verified backup, explicitly run
   `npm run db:preflight -- --resolve --backup <backup-path>`.
 - `CURRENT`: migration and schema already agree.
 - `CONFLICT`: partial or unknown state. Stop and recover manually; do not use
   `db push`, reset, edit applied migrations, or mark anything applied.
 
+The production entrypoint runs this preflight before `prisma migrate deploy`.
+It refuses `ADOPT` and `CONFLICT` states without changing migration history;
+adoption always remains an explicit backup-gated operator action.
+
 Restore drill: stop Study Desk, keep the damaged database as evidence, restore
 the verified backup to a new path, run SQLite `integrity_check` plus
 `npm run db:preflight`, start the same prior application image against the