remember me with max age 30 days :).

frontend/src/lib/auth/rememberMe.ts

@@ -0,0 +1,14 @@
+const REMEMBERED_EMAIL_KEY = 'rememberedEmail';
+
+export function getRememberedEmail(): string {
+  if (typeof window === 'undefined') return '';
+  return localStorage.getItem(REMEMBERED_EMAIL_KEY) ?? '';
+}
+
+export function setRememberedEmail(email: string): void {
+  localStorage.setItem(REMEMBERED_EMAIL_KEY, email);
+}
+
+export function clearRememberedEmail(): void {
+  localStorage.removeItem(REMEMBERED_EMAIL_KEY);
+}