fix(signage/playlist_media): don't cleanup media still in use

src/placeos-rest-api/controllers/signage/playlist_media.cr

@@ -101,6 +101,12 @@ module PlaceOS::Api
         {current_item.media, current_item.thumbnail}.each do |upload|
           next unless upload
 
+          # don't remove upload if it's used else where
+          upload_id = upload.id
+          counts = Model::Playlist::Item.where("media_id = ? OR thumbnail_id = ? AND id != ?", upload_id, upload_id, current_item.id).count
+          next unless counts.zero?
+
+          # cleanup files from storage
           storage = upload.storage || ::PlaceOS::Model::Storage.storage_or_default(authority.id)
           signer = UploadSigner::AmazonS3.new(storage.access_key, storage.decrypt_secret, storage.region, endpoint: storage.endpoint)
           signer.delete_file(storage.bucket_name, upload.object_key, upload.resumable_id)