Add push notification functionality with tests and digest scheduler

- Implemented push subscription API with tests for subscribing and unsubscribing users.
- Created web push notification tests triggered by child actions.
- Added digest scheduler to send email digests to users at 9 PM local time.
- Developed utility functions for creating and validating digest action tokens.
- Integrated web push sender to handle sending notifications to users.
- Added service worker for handling push notifications in the frontend.
- Created a push opt-in component for user notification preferences.
- Implemented tests for the push opt-in component to ensure correct behavior.
- Updated frontend services to manage push subscriptions and permissions.

frontend/vue-app/src/stores/auth.ts

@@ -4,6 +4,7 @@ const hasLocalStorage =
   typeof localStorage !== 'undefined' && typeof localStorage.getItem === 'function'
 const AUTH_SYNC_EVENT_KEY = 'authSyncEvent'
 const PARENT_AUTH_KEY = 'parentAuth'
+const PARENT_RETURN_URL_KEY = 'parentReturnUrl'
 const PARENT_AUTH_EXPIRY_NON_PERSISTENT = 60_000 // 1 minute
 const PARENT_AUTH_EXPIRY_PERSISTENT = 172_800_000 // 2 days
 
@@ -71,6 +72,33 @@ export function enforceParentExpiry() {
   runExpiryCheck()
 }
 
+export function setPendingReturnUrl(url: string) {
+  if (!url.startsWith('/parent')) return
+  if (hasLocalStorage) {
+    localStorage.setItem(PARENT_RETURN_URL_KEY, url)
+  }
+}
+
+export function consumePendingReturnUrl(): string | null {
+  if (!hasLocalStorage) return null
+  const url = localStorage.getItem(PARENT_RETURN_URL_KEY)
+  if (url) {
+    localStorage.removeItem(PARENT_RETURN_URL_KEY)
+  }
+  return url
+}
+
+export function hasPendingReturnUrl(): boolean {
+  if (!hasLocalStorage) return false
+  return localStorage.getItem(PARENT_RETURN_URL_KEY) !== null
+}
+
+export function clearPendingReturnUrl() {
+  if (hasLocalStorage) {
+    localStorage.removeItem(PARENT_RETURN_URL_KEY)
+  }
+}
+
 export function authenticateParent(persistent: boolean) {
   const duration = persistent ? PARENT_AUTH_EXPIRY_PERSISTENT : PARENT_AUTH_EXPIRY_NON_PERSISTENT
   parentAuthExpiresAt.value = Date.now() + duration