feat: Authors feature backend (and upgraded deprecated mods)

test/accept_invitation_atomic_test.go

@@ -93,7 +93,7 @@ func openRealSqlite(t *testing.T) *gorm.DB {
 	if err != nil {
 		t.Fatalf("open sqlite: %v", err)
 	}
-	if err := db.AutoMigrate(&models.Article{}, &models.User{}, &models.Invite{}); err != nil {
+	if err := db.AutoMigrate(&models.Article{}, &models.Author{}, &models.ArticleAuthor{}, &models.User{}, &models.Invite{}); err != nil {
 		t.Fatalf("migrate: %v", err)
 	}
 	t.Cleanup(func() {