Transfer tool finds existing media by source.

src/tools/transfer.js

@@ -455,6 +455,7 @@ async function addReleaseMedia(medias, release, target) {
 
 		const existingMedia = await knex('media')
 			.where('hash', media.hash)
+			.orWhere('source', media.source)
 			.first();
 
 		const id = existingMedia?.id || nanoid();