feat: Authors feature backend (and upgraded deprecated mods)

test/media_persistence_test.go

@@ -18,7 +18,7 @@ import (
 func newMediaPersistence(t *testing.T) (*gorm.DB, *persistence.ImageRepository, string) {
 	t.Helper()
 	db := openInMemoryDb(t)
-	if err := db.AutoMigrate(&models.Article{}, &models.Image{}); err != nil {
+	if err := db.AutoMigrate(&models.Article{}, &models.Author{}, &models.ArticleAuthor{}, &models.Image{}); err != nil {
 		t.Fatalf("failed to migrate: %v", err)
 	}
 	uploadDir := t.TempDir()