fix(backend): map Kratos traits id to loginId in UserSummary API response

backend/internal/handler/user_handler.go

@@ -52,6 +52,7 @@ func NewUserHandler(kratosAdmin service.KratosAdminService, oryProvider OryProvi
 type userSummary struct {
 	ID              string          `json:"id"`
 	Email           string          `json:"email"`
+	LoginID         string          `json:"loginId,omitempty"`
 	Name            string          `json:"name"`
 	Phone           string          `json:"phone"`
 	Role            string          `json:"role"`
@@ -1364,6 +1365,7 @@ func (h *UserHandler) mapIdentitySummary(ctx context.Context, identity service.K
 	summary := userSummary{
 		ID:          identity.ID,
 		Email:       extractTraitString(traits, "email"),
+		LoginID:     extractTraitString(traits, "id"), // id in Kratos traits maps to LoginID
 		Name:        extractTraitString(traits, "name"),
 		Phone:       extractTraitString(traits, "phone_number"),
 		Role:        role,