Updating migration script

README.md

@@ -127,6 +127,14 @@ Set these when Wasabi image storage is ready:
 
 Use a dedicated private bucket and access key for FlockPal images. Grant only the S3 permissions the app needs for that bucket. When `S3_PUBLIC_BASE_URL` is blank, FlockPal stores private object keys and returns short-lived signed URLs for bird photos.
 
+Migrate existing Postgres-stored bird photos after deploying S3 image storage:
+
+```bash
+docker compose -f docker-compose.prod.yml exec backend npm run migrate:bird-photos-to-s3 -- --apply
+```
+
+Run a dry run first by omitting `--apply`. Use `--limit=10` to migrate a small batch, and `--keep-data-url` if you want to leave the original inline image in Postgres during an initial verification pass.
+
 Bucket settings recommendation:
 
 - Enable bucket versioning if you want rollback protection from accidental overwrites or deletes. Add a lifecycle policy once upload volume is known because every object version contributes to stored data.