more refactors

internal/db/permission.go

@@ -24,6 +24,10 @@ type Permission struct {
 	Roles []Role `bun:"m2m:role_permissions,join:Permission=Role"`
 }
 
+func (p Permission) isSystem() bool {
+	return p.IsSystem
+}
+
 // GetPermissionByName queries the database for a permission matching the given name
 // Returns nil, nil if no permission is found
 func GetPermissionByName(ctx context.Context, tx bun.Tx, name permissions.Permission) (*Permission, error) {
@@ -150,26 +154,5 @@ func DeletePermission(ctx context.Context, tx bun.Tx, id int) error {
 	if id <= 0 {
 		return errors.New("id must be positive")
 	}
-
-	// Check if permission is system permission
-	perm, err := GetPermissionByID(ctx, tx, id)
-	if err != nil {
-		return errors.Wrap(err, "GetPermissionByID")
-	}
-	if perm == nil {
-		return errors.New("permission not found")
-	}
-	if perm.IsSystem {
-		return errors.New("cannot delete system permission")
-	}
-
-	_, err = tx.NewDelete().
-		Model((*Permission)(nil)).
-		Where("id = ?", id).
-		Exec(ctx)
-	if err != nil {
-		return errors.Wrap(err, "tx.NewDelete")
-	}
-
-	return nil
+	return DeleteWithProtection[Permission](ctx, tx, id)
 }