refac: repository updates, image attachment and deletes report the domain not-found error for an unknown id, the same for articles, users and images, and the test fakes stop returning GORM errors

test/image_test.go

@@ -7,8 +7,6 @@ import (
 	"io"
 	"strings"
 	"testing"
-
-	"gorm.io/gorm"
 )
 
 var errUnsupportedImageContentType = errors.New("the file must be a PNG, JPEG, WEBP, or SVG image")
@@ -51,7 +49,7 @@ func (m *mockImageRepo) Delete(id uint32) error {
 		return err
 	}
 	if _, ok := m.images[id]; !ok {
-		return gorm.ErrRecordNotFound
+		return imageDomain.ErrImageNotFound
 	}
 	delete(m.images, id)
 	return nil