fix(alarms): harden native alarm lifecycle

lib/servicios/servicio_alarmas_android.dart

@@ -68,6 +68,25 @@ class DiagnosticoAlarmasAndroid {
   }
 }
 
+class EjecucionAlarmaNativa {
+  const EjecucionAlarmaNativa({
+    required this.alarmaId,
+    required this.gestionadaEn,
+  });
+
+  final String alarmaId;
+  final DateTime gestionadaEn;
+
+  factory EjecucionAlarmaNativa.fromMap(Map<Object?, Object?> map) {
+    return EjecucionAlarmaNativa(
+      alarmaId: map['alarmId'] as String? ?? '',
+      gestionadaEn: DateTime.fromMillisecondsSinceEpoch(
+        (map['handledAtMillis'] as num?)?.toInt() ?? 0,
+      ),
+    );
+  }
+}
+
 abstract class PuertoAlarmasAndroid {
   Stream<EventoAlarmaAndroid> get eventosAlarma;
 
@@ -81,6 +100,7 @@ abstract class PuertoAlarmasAndroid {
   Future<void> confirmarAudioFlutter(String alarmaId);
   Future<DiagnosticoAlarmasAndroid> diagnostico();
   Future<EventoAlarmaAndroid?> obtenerEventoInicial();
+  Future<List<EjecucionAlarmaNativa>> obtenerEjecucionesNativasGestionadas();
 }
 
 class ServicioAlarmasAndroid implements PuertoAlarmasAndroid {
@@ -208,6 +228,24 @@ class ServicioAlarmasAndroid implements PuertoAlarmasAndroid {
     return evento.alarmaId.isEmpty ? null : evento;
   }
 
+  @override
+  Future<List<EjecucionAlarmaNativa>>
+  obtenerEjecucionesNativasGestionadas() async {
+    final raw = await _channel.invokeMethod<List<Object?>>(
+      'getHandledAlarmOccurrences',
+    );
+    if (raw == null || raw.isEmpty) return const [];
+    return raw
+        .whereType<Map<Object?, Object?>>()
+        .map(EjecucionAlarmaNativa.fromMap)
+        .where(
+          (evento) =>
+              evento.alarmaId.isNotEmpty &&
+              evento.gestionadaEn.millisecondsSinceEpoch > 0,
+        )
+        .toList();
+  }
+
   Future<void> _logAndInvokeVoid(String method, Map<String, Object?> args) {
     debugPrint('[PluriWave][alarmas] $method $args');
     return _channel.invokeMethod<void>(method, args);