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/components/shared/LoginButton.vue

@@ -8,6 +8,9 @@ import {
   isParentPersistent,
   logoutParent,
   logoutUser,
+  consumePendingReturnUrl,
+  hasPendingReturnUrl,
+  clearPendingReturnUrl,
 } from '../../stores/auth'
 import { getCachedImageUrl, getCachedImageBlob } from '@/common/imageCache'
 import '@/assets/styles.css'
@@ -105,6 +108,7 @@ const close = () => {
   show.value = false
   error.value = ''
   stayInParentMode.value = false
+  clearPendingReturnUrl()
 }
 
 const submit = async () => {
@@ -136,7 +140,8 @@ const submit = async () => {
     // Authenticate parent and navigate
     authenticateParent(stayInParentMode.value)
     close()
-    router.push('/parent')
+    const returnUrl = consumePendingReturnUrl()
+    router.push(returnUrl || '/parent')
   } catch (e) {
     error.value = 'Network error'
   }
@@ -253,6 +258,9 @@ onMounted(() => {
   eventBus.on('profile_updated', fetchUserProfile)
   document.addEventListener('mousedown', handleClickOutside)
   fetchUserProfile()
+  if (!isParentAuthenticated.value && hasPendingReturnUrl()) {
+    open()
+  }
 })
 
 onUnmounted(() => {