ServiceWorker registration fails in Facebook/Instagram in-app browser on iOS

When using the Firebase Messaging service with Angular 19.1.4 in the Facebook/Instagram in-app browser on iOS devices, the following error occurs:
```typescript
TypeError: undefined is not an object (evaluating 'navigator.serviceWorker.addEventListener')
```

### Environment
- **Platform**: iOS
- **Browser**: Facebook/Instagram in-app browser
- **Framework**: Angular 19.1.4
- **Dependencies**:
- @angular/core: 19.1.4
- @angular/common: 19.1.4
- @angular/platform-browser: 19.1.4
- **Service**: Firebase Cloud Messaging

### Technical Details
The error occurs during the messaging service initialization when attempting to add an event listener to the ServiceWorker. The specific line causing the issue is:
```typescript
navigator.serviceWorker.addEventListener('message', e => messageEventListener(messaging as MessagingService, e));
```

### Root Cause
The Facebook/Instagram in-app browser on iOS does not support or properly expose the ServiceWorker API, causing `navigator.serviceWorker` to be undefined. This issue persists even with the latest Angular 19 framework.

### Impact
- Firebase Cloud Messaging service initialization fails
- Push notifications cannot be registered or received
- Affects only users accessing the Angular 19 application through Facebook/Instagram in-app browser on iOS devices

Comienza con la llamada de inicialización de messaging-service mostrada en el issue y reprodúcela en el navegador integrado en la aplicación iOS de Facebook/Instagram. Rastrea cómo se accede a navigator.serviceWorker; se considera terminado cuando la inicialización ya no produce errores si la API no está disponible y el comportamiento de push se ha verificado donde sea compatible.

Escrito por el modelo de indexación a partir del texto del issue.