refac: DELETE /v1/user/{id}?expected_role_id=N, user.remove audit event, 409 target_role_not_found, GetAll returns its error, Own-scope visibility filter moved into repos, JSON tags removed from use-case types

api/handlers/role/roleHandler.go

@@ -119,6 +119,7 @@ var refusals = []refusal{
 	{domain.ErrRoleNameTaken, http.StatusConflict, apperr.RoleNameTakenErrorMessage},
 	{domain.ErrRoleConflict, http.StatusConflict, apperr.RoleConflictErrorMessage},
 	{domain.ErrRoleHasMembers, http.StatusConflict, apperr.RoleHasMembersErrorMessage},
+	{domain.ErrReassignTargetNotFound, http.StatusConflict, apperr.ReassignTargetNotFoundErrorMessage},
 	{domain.ErrInvalidReassign, http.StatusBadRequest, apperr.InvalidReassignErrorMessage},
 	{domain.ErrInvalidRoleName, http.StatusBadRequest, apperr.InvalidRoleNameErrorMessage},
 	{domain.ErrUnknownPermission, http.StatusBadRequest, apperr.UnknownPermissionErrorMessage},