feat: Implement secure VAPID key generation for push notifications

- Replace random key generation with the web-push library for generating cryptographically secure VAPID keys.
- Update console output to guide users on adding keys to their environment configuration.
- Enhance error handling for VAPID key generation issues.
- Add web-push dependency to package.json and package-lock.json for proper functionality.

src/components/nostr/IdentityDialog.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { ref, computed, watch } from 'vue'
+import { ref, computed } from 'vue'
 import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle } from '@/components/ui/dialog'
 import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs'
 import { Button } from '@/components/ui/button'

src/lib/notifications/push.ts

@@ -101,11 +101,15 @@ export class PushNotificationService {
       // Check if already subscribed
       const existingSubscription = await registration.pushManager.getSubscription()
       if (existingSubscription) {
+        console.log('Using existing push subscription')
         return this.subscriptionToData(existingSubscription)
       }
 
       // Create new subscription
+      console.log('Creating new push subscription with VAPID key:', config.push.vapidPublicKey.substring(0, 20) + '...')
+      
       const applicationServerKey = this.urlBase64ToUint8Array(config.push.vapidPublicKey)
+      console.log('VAPID key converted to Uint8Array, length:', applicationServerKey.length)
       
       const subscription = await registration.pushManager.subscribe({
         userVisibleOnly: true,
@@ -114,11 +118,26 @@ export class PushNotificationService {
 
       const subscriptionData = this.subscriptionToData(subscription)
       
-      console.log('Push subscription created:', subscriptionData)
+      console.log('Push subscription created successfully:', {
+        endpoint: subscriptionData.endpoint,
+        hasKeys: !!subscriptionData.keys.p256dh && !!subscriptionData.keys.auth
+      })
       return subscriptionData
 
     } catch (error) {
       console.error('Failed to subscribe to push notifications:', error)
+      
+      // Provide more specific error information
+      if (error instanceof DOMException) {
+        if (error.name === 'InvalidStateError') {
+          console.error('VAPID key format issue detected. Please check your VAPID public key.')
+        } else if (error.name === 'NotAllowedError') {
+          console.error('Push notifications blocked by user or browser policy.')
+        } else if (error.name === 'NotSupportedError') {
+          console.error('Push notifications not supported by this browser.')
+        }
+      }
+      
       throw error
     }
   }