feat: image variants engine

internal/infrastructure/useCases/auditFailures.go

@@ -29,6 +29,7 @@ var failureReasons = []failureReason{
 	{image.ErrInvalidMergeRequest, "The merge request is not valid."},
 	{image.ErrMergeCopyMissing, "One of the copies no longer exists."},
 	{image.ErrMergeHashMismatch, "The images are not identical copies."},
+	{image.ErrVariantExists, "A variant with that name already exists."},
 	{purge.ErrPurgeConflict, "The library changed since the preview. Review it again."},
 	{purge.ErrPurgeBusy, "A purge is already running."},
 	{user.ErrRegistrationClosed, "Registration is closed on this site."},
@@ -65,6 +66,7 @@ var downloadFailureReasons = map[string]string{
 var notFoundCauses = []error{
 	article.ErrArticleNotFound,
 	image.ErrImageNotFound,
+	image.ErrVariantNotFound,
 	invite.ErrInviteNotFound,
 	user.ErrUserNotFound,
 }