refac: decouple persistence and image storage behind driver registries

test/media_cleanup_test.go

@@ -60,7 +60,7 @@ func TestMediaMergeRewritesArticlesInIdOrder(t *testing.T) {
 		env.seedArticle(id, "Article", true, env.urlOf(3))
 	}
 	recorder := &mediaOrderRecordingArticleRepo{mockArticleRepo: env.articles}
-	uc := useCases.NewMergeMediaUseCase(env.images, recorder)
+	uc := useCases.NewMergeMediaUseCase(env.images, recorder, env.storage)
 
 	if _, err := uc.Merge(2, []uint32{3}); err != nil {
 		t.Fatalf("unexpected error: %v", err)