fix: Cast applicationServerKey to ArrayBuffer for strict TypeScript

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/hooks/usePushNotifications.ts

@@ -144,9 +144,10 @@ export function usePushNotifications(options: UsePushNotificationsOptions = {})
       }
 
       // Subscribe to push notifications
+      const applicationServerKey = urlBase64ToUint8Array(VAPID_PUBLIC_KEY);
       const pushSubscription = await registration.pushManager.subscribe({
         userVisibleOnly: true,
-        applicationServerKey: urlBase64ToUint8Array(VAPID_PUBLIC_KEY),
+        applicationServerKey: applicationServerKey.buffer as ArrayBuffer,
       });
 
       console.log('Push subscription created:', pushSubscription);