chore: add "pnpm run migrations:revert" command (#23869)

docs/docs/developer/database-migrations.md

@@ -12,3 +12,13 @@ pnpm run migrations:generate <migration-name>
 3. Move the migration file to folder `./server/src/schema/migrations` in your code editor.
 
 The server will automatically detect `*.ts` file changes and restart. Part of the server start-up process includes running any new migrations, so it will be applied immediately.
+
+## Reverting a Migration
+
+If you need to undo the most recently applied migration—for example, when developing or testing on schema changes—run:
+
+```bash
+pnpm run migrations:revert
+```
+
+This command rolls back the latest migration and brings the database schema back to its previous state.