feat: Implement push notification system for admin announcements

- Add a notification manager to handle push notifications and integrate with Nostr events.
- Create a push notification service to manage subscription and permission requests.
- Introduce components for notification settings and permission prompts in the UI.
- Update Nostr store to manage push notification state and enable/disable functionality.
- Enhance NostrFeed to send notifications for new admin announcements.
- Implement test notification functionality for development purposes.

src/stores/nostr.ts

@@ -2,6 +2,7 @@ import { defineStore } from 'pinia'
 import { ref } from 'vue'
 import { NostrClient } from '@/lib/nostr/client'
 import { config } from '@/lib/config'
+import { pushService, type PushSubscriptionData } from '@/lib/notifications/push'
 
 // Define an interface for the account object
 interface NostrAccount {
@@ -19,6 +20,10 @@ export const useNostrStore = defineStore('nostr', () => {
   const relayUrls = ref<string[]>(config.nostr.relays)
   const account = ref<NostrAccount | null>(null)
   
+  // Push notifications
+  const pushSubscription = ref<PushSubscriptionData | null>(null)
+  const notificationsEnabled = ref(false)
+  
   // Singleton client instance
   let client: NostrClient | null = null
 
@@ -77,6 +82,78 @@ export const useNostrStore = defineStore('nostr', () => {
     account.value = nostrAccount
   }
 
+  // Push notification management
+  async function enablePushNotifications(): Promise<PushSubscriptionData> {
+    try {
+      const subscription = await pushService.subscribe()
+      pushSubscription.value = subscription
+      notificationsEnabled.value = true
+      
+      // Store subscription in localStorage for persistence
+      localStorage.setItem('push-subscription', JSON.stringify(subscription))
+      localStorage.setItem('notifications-enabled', 'true')
+      
+      return subscription
+    } catch (error) {
+      console.error('Failed to enable push notifications:', error)
+      throw error
+    }
+  }
+
+  async function disablePushNotifications(): Promise<void> {
+    try {
+      await pushService.unsubscribe()
+      pushSubscription.value = null
+      notificationsEnabled.value = false
+      
+      // Remove from localStorage
+      localStorage.removeItem('push-subscription')
+      localStorage.removeItem('notifications-enabled')
+    } catch (error) {
+      console.error('Failed to disable push notifications:', error)
+      throw error
+    }
+  }
+
+  async function checkPushNotificationStatus(): Promise<void> {
+    try {
+      // Check localStorage first
+      const storedEnabled = localStorage.getItem('notifications-enabled') === 'true'
+      const storedSubscription = localStorage.getItem('push-subscription')
+      
+      if (storedEnabled && storedSubscription) {
+        pushSubscription.value = JSON.parse(storedSubscription)
+        notificationsEnabled.value = true
+      }
+
+      // Verify with push service
+      const currentSubscription = await pushService.getSubscription()
+      if (currentSubscription) {
+        pushSubscription.value = currentSubscription
+        notificationsEnabled.value = true
+      } else if (storedEnabled) {
+        // Stored state says enabled but no actual subscription - clear stored state
+        await disablePushNotifications()
+      }
+    } catch (error) {
+      console.error('Failed to check push notification status:', error)
+    }
+  }
+
+  // Send test notification
+  async function sendTestNotification(): Promise<void> {
+    await pushService.showLocalNotification({
+      title: '🚨 Test Admin Announcement',
+      body: 'This is a test notification to verify push notifications are working correctly.',
+      icon: '/pwa-192x192.png',
+      tag: 'test-notification',
+      data: {
+        url: '/',
+        type: 'admin-announcement'
+      }
+    })
+  }
+
   return {
     // State
     isConnected,
@@ -84,6 +161,8 @@ export const useNostrStore = defineStore('nostr', () => {
     error,
     relayUrls,
     account,
+    pushSubscription,
+    notificationsEnabled,
     
     // Actions
     connect,
@@ -92,5 +171,9 @@ export const useNostrStore = defineStore('nostr', () => {
     setConnected,
     setRelayUrls,
     setAccount,
+    enablePushNotifications,
+    disablePushNotifications,
+    checkPushNotificationStatus,
+    sendTestNotification,
   }
 })