test(backend): add unit tests for user group management and fix interface inconsistencies

backend/internal/domain/auth_models.go

@@ -80,6 +80,7 @@ type UserProfileResponse struct {
 	RelyingPartyID  *string        `json:"relyingPartyId,omitempty"` // 추가
 	Metadata        map[string]any `json:"metadata,omitempty"`
 	Tenant          *Tenant        `json:"tenant,omitempty"`
+	ManageableTenants []Tenant       `json:"manageableTenants,omitempty"` // 추가: 관리 가능한 테넌트 목록
 }
 
 type UpdateUserRequest struct {