feat(audio): audio session integration and runtime robustness

- Integrate audio_session (new servicio_audio_session.dart): incoming calls pause the radio and resume on end, headphone unplug pauses without auto-resume, permanent focus loss never auto-resumes, duck lowers volume
- Add play-intent flag to ServicioAudio so interruption handling and future reconnect logic can distinguish user pause from system-driven stops
- Eliminate read-modify-write race in ServicioAlarmas with an in-memory cache and single-writer queue across all mutations; recalcularTodas persists only when state actually changed
- Convert ServicioAlarmasAndroid static StreamController/handler to injectable instance fields, restoring test isolation
- Inject a single cached SharedPreferences from main.dart across services and state (removes 23 inline getInstance() calls)
- Move configurarLocalizaciones out of MiniReproductor.build() (was running on every rebuild during playback)
- Bound the alarm fire-dedup set (cap 200 entries, 24h pruning)
- 12 new tests (89 total green), flutter analyze clean

lib/estado/estado_alarmas.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter/foundation.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
+import '../l10n/gen/app_localizations.dart';
 import '../modelos/alarma_musical.dart';
 import '../servicios/servicio_alarmas.dart';
 import '../servicios/servicio_alarmas_android.dart';
@@ -13,7 +14,7 @@ class EstadoAlarmas extends ChangeNotifier {
     PuertoAlarmasAndroid? android,
     SharedPreferences? prefs,
     bool iniciarAutomaticamente = true,
-  }) : servicio = servicio ?? ServicioAlarmas(),
+  }) : servicio = servicio ?? ServicioAlarmas(prefs: prefs),
        android = android ?? ServicioAlarmasAndroid(),
        _prefs = prefs {
     // Decision 2.1 (snooze sync): the native layer reports its own snoozes
@@ -43,6 +44,12 @@ class EstadoAlarmas extends ChangeNotifier {
       StreamController<AlarmaMusical>.broadcast();
   final Set<String> _ejecucionesEmitidas = {};
   static const _margenDisparoLocal = Duration(seconds: 45);
+
+  // Bounds for _ejecucionesEmitidas (S3-R6): entries older than the
+  // retention window are pruned; the set never exceeds the cap.
+  static const _retencionEjecucionesEmitidas = Duration(hours: 24);
+  @visibleForTesting
+  static const maxEjecucionesEmitidas = 200;
   bool _cargando = false;
   String? _error;
 
@@ -128,12 +135,22 @@ class EstadoAlarmas extends ChangeNotifier {
     final proxima = alarma.proximaProgramable;
     if (proxima == null) return;
     final key = '${alarma.id}:${proxima.millisecondsSinceEpoch}';
-    _ejecucionesEmitidas.add(key);
+    _registrarEjecucionEmitida(key);
     debugPrint(
       '[PluriWave][alarmas] ejecucion gestionada id=${alarma.id} proxima=${proxima.toIso8601String()}',
     );
   }
 
+  @visibleForTesting
+  int get ejecucionesEmitidasLength => _ejecucionesEmitidas.length;
+
+  /// Forwards the UI localizations to the native bridge so alarm and station
+  /// names sent to Android follow the app locale (Decision 3.2 — replaces
+  /// the old static `ServicioAlarmasAndroid.configurarLocalizaciones`).
+  void configurarLocalizaciones(AppLocalizations l10n) {
+    android.configurarLocalizaciones(l10n);
+  }
+
   Future<void> eliminarAlarma(String id) async {
     debugPrint('[PluriWave][alarmas] eliminar id=$id');
     final config = await servicio.eliminarAlarma(id);
@@ -415,6 +432,7 @@ class EstadoAlarmas extends ChangeNotifier {
 
   void _vigilarAlarmasVencidas() {
     final ahora = DateTime.now();
+    _depurarEjecucionesEmitidas(ahora);
     for (final alarma in _alarmas) {
       final proxima = alarma.proximaProgramable;
       if (!alarma.activa || proxima == null) continue;
@@ -422,13 +440,13 @@ class EstadoAlarmas extends ChangeNotifier {
       final key = '${alarma.id}:${proxima.millisecondsSinceEpoch}';
       final retraso = ahora.difference(proxima);
       if (retraso > _margenDisparoLocal) {
-        _ejecucionesEmitidas.add(key);
+        _registrarEjecucionEmitida(key);
         debugPrint(
           '[PluriWave][alarmas] vencida local ignorada por antigua id=${alarma.id} proxima=${proxima.toIso8601String()} retraso=${retraso.inSeconds}s',
         );
         continue;
       }
-      if (_ejecucionesEmitidas.add(key)) {
+      if (_registrarEjecucionEmitida(key)) {
         debugPrint(
           '[PluriWave][alarmas] vencida local id=${alarma.id} proxima=${proxima.toIso8601String()}',
         );
@@ -437,6 +455,37 @@ class EstadoAlarmas extends ChangeNotifier {
     }
   }
 
+  /// Adds a `alarmId:millis` key and keeps the set bounded (S3-R6).
+  /// Returns whether the key was newly added (fire-dedup contract).
+  bool _registrarEjecucionEmitida(String key) {
+    final agregada = _ejecucionesEmitidas.add(key);
+    _depurarEjecucionesEmitidas(DateTime.now());
+    return agregada;
+  }
+
+  void _depurarEjecucionesEmitidas(DateTime ahora) {
+    final limite =
+        ahora.subtract(_retencionEjecucionesEmitidas).millisecondsSinceEpoch;
+    _ejecucionesEmitidas.removeWhere((key) => _millisDeEjecucion(key) < limite);
+    if (_ejecucionesEmitidas.length <= maxEjecucionesEmitidas) return;
+    // Still over the cap: evict the oldest occurrences first. Pruned keys
+    // cannot re-fire because occurrences beyond _margenDisparoLocal are
+    // ignored by _vigilarAlarmasVencidas anyway.
+    final ordenadas =
+        _ejecucionesEmitidas.toList()..sort(
+          (a, b) => _millisDeEjecucion(a).compareTo(_millisDeEjecucion(b)),
+        );
+    _ejecucionesEmitidas.removeAll(
+      ordenadas.take(_ejecucionesEmitidas.length - maxEjecucionesEmitidas),
+    );
+  }
+
+  int _millisDeEjecucion(String key) {
+    final separador = key.lastIndexOf(':');
+    if (separador < 0) return 0;
+    return int.tryParse(key.substring(separador + 1)) ?? 0;
+  }
+
   @override
   void dispose() {
     _refresco?.cancel();