feat: add select-authenticator page

src/login/Fallback.tsx

@@ -26,6 +26,7 @@ const LogoutConfirm = lazy(() => import("keycloakify/login/pages/LogoutConfirm")
 const UpdateUserProfile = lazy(() => import("keycloakify/login/pages/UpdateUserProfile"));
 const IdpReviewUserProfile = lazy(() => import("keycloakify/login/pages/IdpReviewUserProfile"));
 const UpdateEmail = lazy(() => import("keycloakify/login/pages/UpdateEmail"));
+const SelectAuthenticator = lazy(() => import("keycloakify/login/pages/SelectAuthenticator"));
 
 export default function Fallback(props: PageProps<KcContext, I18n>) {
     const { kcContext, ...rest } = props;
@@ -78,6 +79,8 @@ export default function Fallback(props: PageProps<KcContext, I18n>) {
                         return <IdpReviewUserProfile kcContext={kcContext} {...rest} />;
                     case "update-email.ftl":
                         return <UpdateEmail kcContext={kcContext} {...rest} />;
+                    case "select-authenticator.ftl":
+                        return <SelectAuthenticator kcContext={kcContext} {...rest} />;
                 }
                 assert<Equals<typeof kcContext, never>>(false);
             })()}