fix(admin): align batch-limits test with expanded NewUserHandler signature

PR #4425 was authored before #4429 widened NewUserHandler with the
step-up TOTP and user services, and merged without a rebase, breaking
typecheck on main.

backend/internal/handler/admin/user_handler_batch_limits_test.go

@@ -44,7 +44,7 @@ func (s *batchLimitsAdminServiceStub) BatchUpdateLimits(_ context.Context, userI
 func setupBatchLimitsRouter(serviceStub service.AdminService) *gin.Engine {
 	gin.SetMode(gin.TestMode)
 	router := gin.New()
-	handler := NewUserHandler(serviceStub, nil, nil, nil)
+	handler := NewUserHandler(serviceStub, nil, nil, nil, nil, nil)
 	router.POST("/api/v1/admin/users/batch-limits", handler.BatchUpdateLimits)
 	return router
 }