Add localization support for search and alarm features in multiple languages

- Updated Japanese, Portuguese, Russian, and Chinese localization files with new strings for search and alarm functionalities.
- Enhanced the search screen with localized titles, subtitles, and filter labels.
- Integrated localization into the alarm screen, including actions and messages related to alarm management.
- Refactored country and language lists to use localized keys for better maintainability.
- Improved user experience by providing localized hints and messages throughout the application.

lib/pantallas/pantalla_alarma_sonando.dart

@@ -5,6 +5,7 @@ import 'package:just_audio/just_audio.dart';
 import 'package:provider/provider.dart';
 
 import '../estado/estado_alarmas.dart';
+import '../l10n/gen/app_localizations.dart';
 import '../estado/estado_radio.dart';
 import '../modelos/alarma_musical.dart';
 import '../servicios/servicio_audio.dart';
@@ -152,6 +153,7 @@ class _PantallaAlarmaSonandoState extends State<PantallaAlarmaSonando> {
   @override
   Widget build(BuildContext context) {
     final alarma = widget.alarma;
+    final l10n = AppLocalizations.of(context);
     return Scaffold(
       backgroundColor: const Color(0xFF061722),
       body: SafeArea(
@@ -197,7 +199,7 @@ class _PantallaAlarmaSonandoState extends State<PantallaAlarmaSonando> {
                   FilledButton.icon(
                     onPressed: _detener,
                     icon: const Icon(Icons.stop_rounded),
-                    label: const Text('Detener alarma'),
+                    label: Text(l10n.stopAlarmAction),
                   ),
                 ],
               ),