refactor(auth): provide FirebaseAuthenticator in root middleware

Updates the root middleware to provide the `IFirebaseAuthenticator` service to the request context. This makes the service available for injection throughout the application.

Author: fulleni

routes/_middleware.dart

@@ -10,6 +10,7 @@ import 'package:flutter_news_app_api_server_full_source_code/src/registry/data_o
 import 'package:flutter_news_app_api_server_full_source_code/src/registry/model_registry.dart';
 import 'package:flutter_news_app_api_server_full_source_code/src/services/auth_service.dart';
 import 'package:flutter_news_app_api_server_full_source_code/src/services/auth_token_service.dart';
+import 'package:flutter_news_app_api_server_full_source_code/src/services/firebase_authenticator.dart';
 import 'package:flutter_news_app_api_server_full_source_code/src/services/country_query_service.dart';
 import 'package:flutter_news_app_api_server_full_source_code/src/services/dashboard_summary_service.dart';
 import 'package:flutter_news_app_api_server_full_source_code/src/services/push_notification_service.dart';
@@ -143,6 +144,11 @@ Handler middleware(Handler handler) {
                   (_) => deps.pushNotificationService,
                 ),
               )
+              .use(
+                provider<IFirebaseAuthenticator>(
+                  (_) => deps.firebaseAuthenticator,
+                ),
+              )
               .use(provider<EmailRepository>((_) => deps.emailRepository))
               .use(
                 provider<TokenBlacklistService>(