feat: Add persistent global notification settings for admin panel

Implement database-backed notification settings that persist across restarts:

Backend changes:
- Updated DashboardService to read/write notification settings from database
- Added 6 notification settings keys to dbSettingsMap:
  * enable_email_notifications (boolean)
  * enable_push_notifications (boolean)
  * admin_notifications (boolean)
  * error_alerts (boolean)
  * new_user_alerts (boolean)
  * system_health_alerts (boolean)
- Settings are now retrieved from database with fallback defaults

Database:
- Seeded 6 default notification settings in settings table
- All notification toggles default to 'true'
- Settings persist across server restarts

Frontend:
- Admin settings page at /settings already configured
- Notifications tab contains all 6 toggle switches
- Settings are loaded from GET /api/v1/admin/dashboard/settings
- Settings are saved via POST /api/v1/admin/dashboard/settings

API Endpoints (already existed, now enhanced):
- GET /api/v1/admin/dashboard/settings - Returns all settings including notifications
- POST /api/v1/admin/dashboard/settings - Persists notification settings to database

Files modified:
- maternal-app-backend/src/modules/admin/dashboard/dashboard.service.ts

Benefits:
✅ Global notification settings are now persistent
✅ Admin can control email/push notifications globally
✅ Admin can configure alert preferences
✅ Settings survive server restarts and deployments

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

maternal-web/public/push-sw.js

@@ -0,0 +1,121 @@
+/* eslint-disable no-restricted-globals */
+// ParentFlow Push Notifications Service Worker
+// Version: 1.0.0
+
+console.log('[Push SW] Service Worker loaded');
+
+// Push event - handle incoming push notifications
+self.addEventListener('push', (event) => {
+  console.log('[Push SW] Push notification received');
+
+  let data = {
+    title: 'ParentFlow',
+    body: 'You have a new notification',
+    icon: '/icons/icon-192x192.png',
+    badge: '/icons/icon-72x72.png',
+    tag: 'default',
+  };
+
+  if (event.data) {
+    try {
+      data = event.data.json();
+      console.log('[Push SW] Push data:', data);
+    } catch (error) {
+      console.error('[Push SW] Error parsing push data:', error);
+      data.body = event.data.text();
+    }
+  }
+
+  const options = {
+    body: data.body,
+    icon: data.icon || '/icons/icon-192x192.png',
+    badge: data.badge || '/icons/icon-72x72.png',
+    tag: data.tag || 'default',
+    data: data.data || {},
+    requireInteraction: data.requireInteraction || false,
+    vibrate: [200, 100, 200],
+    actions: data.actions || [],
+    timestamp: data.timestamp || Date.now(),
+  };
+
+  event.waitUntil(
+    self.registration.showNotification(data.title || 'ParentFlow', options)
+  );
+});
+
+// Notification click event - handle user interaction
+self.addEventListener('notificationclick', (event) => {
+  console.log('[Push SW] Notification clicked:', event.notification.tag);
+  console.log('[Push SW] Notification data:', event.notification.data);
+
+  event.notification.close();
+
+  const urlToOpen = event.notification.data?.url || '/';
+  const fullUrl = new URL(urlToOpen, self.location.origin).href;
+
+  event.waitUntil(
+    clients.matchAll({
+      type: 'window',
+      includeUncontrolled: true,
+    }).then((clientList) => {
+      // Check if there's already a window open with this URL
+      for (const client of clientList) {
+        if (client.url === fullUrl && 'focus' in client) {
+          console.log('[Push SW] Focusing existing window');
+          return client.focus();
+        }
+      }
+
+      // Check if there's any window open to the app
+      for (const client of clientList) {
+        if (client.url.startsWith(self.location.origin) && 'focus' in client) {
+          console.log('[Push SW] Navigating existing window');
+          return client.focus().then(() => client.navigate(urlToOpen));
+        }
+      }
+
+      // If no window is open, open a new one
+      if (clients.openWindow) {
+        console.log('[Push SW] Opening new window');
+        return clients.openWindow(fullUrl);
+      }
+    })
+  );
+});
+
+// Notification close event - track dismissals
+self.addEventListener('notificationclose', (event) => {
+  console.log('[Push SW] Notification closed:', event.notification.tag);
+
+  // Optional: send analytics or update notification status
+  const notificationId = event.notification.data?.notificationId;
+  if (notificationId) {
+    // Could send a beacon to track dismissals
+    console.log('[Push SW] Notification dismissed:', notificationId);
+  }
+});
+
+// Message event - handle messages from the app
+self.addEventListener('message', (event) => {
+  console.log('[Push SW] Message received:', event.data);
+
+  if (event.data && event.data.type === 'SKIP_WAITING') {
+    self.skipWaiting();
+  }
+
+  if (event.data && event.data.type === 'GET_VERSION') {
+    event.ports[0].postMessage({ version: '1.0.0' });
+  }
+
+  if (event.data && event.data.type === 'TEST_NOTIFICATION') {
+    self.registration.showNotification('Test Notification', {
+      body: 'This is a test notification from ParentFlow',
+      icon: '/icons/icon-192x192.png',
+      badge: '/icons/icon-72x72.png',
+      tag: 'test',
+      data: { url: '/' },
+    });
+  }
+});
+
+console.log('[Push SW] Service Worker ready for push notifications');