feat(eq): restyle equalizer screen and add custom presets

Restyle the Ecualizador settings screen to the new visual language while
keeping the equalizer at 5 bands (spike-resolved, Engram id 2498 - band
count is device-reported via just_audio's AndroidEqualizer, not app-chosen;
the approved mockup's 7 sliders would silently no-op on typical hardware).

- Restyle EcualizadorWidget in place: strip its internal title + preset
  chip row (the pushed screen's header now carries the title), add a
  habilitado parameter that greys/disables every slider when EQ is off.
  Widen PresetsEcualizadorWidget additively (personalizados param) so
  custom presets can join the chip row without a second implementation.
- Add servicio_presets_personalizados.dart (new file, own SharedPreferences
  key eq_custom_presets_v1) for custom EQ preset persistence - kept out of
  servicio_ecualizador.dart, which has an empty-git-diff success criterion
  for this change. preset_ecualizador.dart is unchanged: a custom preset is
  just a PresetEcualizador with a user-supplied name.
- Extend EstadoEcualizador with presetsPersonalizados,
  guardarPresetPersonalizado (validates non-empty name),
  eliminarPresetPersonalizado. The load is a new explicit
  cargarPresetsPersonalizados(), deliberately NOT folded into
  cargarPersistido(): that method is exercised ~30 times by
  estado_ecualizador_test.dart (protected, must stay unmodified) via Fakes
  only, with no SharedPreferences awareness in that file.
- Build out the Ecualizador screen body: base-vs-per-station explainer
  banner, a "Salida activa" row surfaced on the main screen (previously
  Advanced-only), an "Emisoras con ajuste propio" drill-down sourced from
  the existing presetsPorEmisora map, and a "Guardar como preset" action.

New coverage lives in new files rather than touching the three protected
EQ test files: ecualizador_widget_test.dart (component-level, did not
exist before this commit), servicio_presets_personalizados_test.dart, and
estado_ecualizador_presets_personalizados_test.dart. servicio_ecualizador.dart,
servicio_audio.dart and the three protected EQ test files keep an empty
git diff. Full suite: 713/713 green (2 skipped, unchanged), up from 682.

size:exception - realized 1,954 changed lines (25 files, plus this docs
update) against the 400-550 forecast: lib/ + ARB alone is ~650 lines, near
the top of the forecast band by itself since this WU also had to build out
a screen body WU3a only stubbed; the rest is 4 test files (675 lines) and
11 new ARB keys regenerating 13 lib/l10n/gen files (~546 lines) - the same
pattern every prior work unit in this branch has hit. Not splittable: WU14
reuses this unit's editor component by exact runtime type and cannot begin
until this lands as a whole.

lib/estado/estado_ecualizador.dart

@@ -7,6 +7,7 @@ import '../modelos/preset_ecualizador.dart';
 import '../servicios/servicio_audio.dart';
 import '../servicios/servicio_dispositivo_audio.dart';
 import '../servicios/servicio_ecualizador.dart';
+import '../servicios/servicio_presets_personalizados.dart';
 
 /// Equalizer state extracted from `EstadoRadio` (S4-R1).
 ///
@@ -30,8 +31,11 @@ class EstadoEcualizador extends ChangeNotifier {
     required this.audio,
     ServicioEcualizador? servicio,
     ServicioDispositivoAudio? dispositivoAudio,
+    ServicioPresetsPersonalizados? presetsPersonalizadosService,
     String? Function()? emisoraActualUuid,
   }) : servicio = servicio ?? ServicioEcualizador(),
+       _presetsPersonalizadosService =
+           presetsPersonalizadosService ?? ServicioPresetsPersonalizados(),
        _dispositivoAudio = dispositivoAudio,
        _emisoraActualUuid = emisoraActualUuid ?? (() => null);
 
@@ -39,6 +43,12 @@ class EstadoEcualizador extends ChangeNotifier {
   final ServicioEcualizador servicio;
   final ServicioDispositivoAudio? _dispositivoAudio;
 
+  /// Persistence for user-named custom presets (design ADR-5 hazard box).
+  /// Deliberately a SEPARATE service/key from [servicio] — see
+  /// [cargarPresetsPersonalizados] for why its load is not folded into
+  /// [cargarPersistido].
+  final ServicioPresetsPersonalizados _presetsPersonalizadosService;
+
   /// Callback into the owner (EstadoRadio) for the currently playing station;
   /// keeps this notifier free of any station-list coupling.
   final String? Function() _emisoraActualUuid;
@@ -61,6 +71,11 @@ class EstadoEcualizador extends ChangeNotifier {
   /// every session without needing a SharedPreferences key or migration.
   final Map<String, String> _nombresPlataforma = {};
 
+  /// User-named custom presets (WU13). Loaded explicitly via
+  /// [cargarPresetsPersonalizados], not as part of [cargarPersistido] —
+  /// see that method's doc for why.
+  List<PresetEcualizador> _presetsPersonalizados = [];
+
   PresetEcualizador _presetPrincipal = PresetEcualizador.flat;
   PresetEcualizador _presetActual = PresetEcualizador.flat;
   bool _activo = true;
@@ -88,6 +103,9 @@ class EstadoEcualizador extends ChangeNotifier {
   Map<String, PresetEcualizador> get presetsMatriz =>
       Map.unmodifiable(_presetsMatriz);
 
+  List<PresetEcualizador> get presetsPersonalizados =>
+      List.unmodifiable(_presetsPersonalizados);
+
   bool get emisoraActualTienePresetPropio {
     final uuid = _emisoraActualUuid();
     if (uuid == null) return false;
@@ -424,6 +442,52 @@ class EstadoEcualizador extends ChangeNotifier {
     }
   }
 
+  /// Loads the persisted custom-preset list (WU13, `eq-custom-presets`
+  /// spec — the Settings EQ screen's preset chip row).
+  ///
+  /// Deliberately NOT part of [cargarPersistido]: that method is exercised
+  /// roughly 30 times by `estado_ecualizador_test.dart` — one of this
+  /// change's protected EQ test files, required to pass **unmodified** —
+  /// via Fakes for [servicio]/[_dispositivoAudio] only, with no
+  /// SharedPreferences awareness anywhere in that file. Folding a third,
+  /// always-real-by-default collaborator into [cargarPersistido] would
+  /// introduce a real SharedPreferences call into every one of those
+  /// cases. Called explicitly by the Settings EQ screen instead, the same
+  /// way `refrescarDispositivoActual` is already called from screen
+  /// `initState`, not from [cargarPersistido].
+  Future<void> cargarPresetsPersonalizados() async {
+    _presetsPersonalizados = await _presetsPersonalizadosService.listar();
+    notifyListeners();
+  }
+
+  /// Saves the CURRENT effective preset's bands (`presetActual`) as a new
+  /// named custom preset (spec "Custom Preset Save").
+  ///
+  /// Returns `false` — and persists nothing — when [nombre] is empty or
+  /// whitespace-only (spec "Custom Preset Naming Validates Non-Empty
+  /// Input"), the same non-crashing validate-before-persist shape
+  /// [renombrarDispositivo] already uses elsewhere in this class.
+  Future<bool> guardarPresetPersonalizado(String nombre) async {
+    final nombreValido = nombre.trim();
+    if (nombreValido.isEmpty) return false;
+
+    final preset = PresetEcualizador(
+      nombre: nombreValido,
+      bandas: List<double>.from(_presetActual.bandas),
+    );
+    await _presetsPersonalizadosService.guardar(preset);
+    _presetsPersonalizados = await _presetsPersonalizadosService.listar();
+    notifyListeners();
+    return true;
+  }
+
+  /// Removes the custom preset named [nombre], if present.
+  Future<void> eliminarPresetPersonalizado(String nombre) async {
+    await _presetsPersonalizadosService.eliminar(nombre);
+    _presetsPersonalizados = await _presetsPersonalizadosService.listar();
+    notifyListeners();
+  }
+
   /// Persists a custom display name for [deviceId].
   ///
   /// Empty names are silently ignored so the existing name is preserved.

lib/l10n/app_en.arb

@@ -95,6 +95,17 @@
   "equalizerPerStationTitle": "Use custom EQ for this favorite",
   "equalizerPerStationActive": "Active for {stationName}",
   "equalizerPerStationMain": "Using main EQ for {stationName}",
+  "equalizerBaseExplainer": "This is the base equalizer: it applies to every station without its own setting. A station's own EQ is set from its own playback screen and overrides this one.",
+  "equalizerActiveOutputLabel": "Active output",
+  "equalizerActiveOutputDefault": "This device's speaker",
+  "equalizerStationsWithOwnEqTitle": "Stations with their own EQ",
+  "equalizerStationsWithOwnEqSubtitle": "Ignore this base equalizer",
+  "equalizerStationsWithOwnEqEmpty": "No stations have their own EQ yet.",
+  "equalizerSaveAsPresetAction": "Save as preset",
+  "equalizerSavePresetDialogTitle": "Save as preset",
+  "equalizerSavePresetNameLabel": "Preset name",
+  "equalizerSavePresetEmptyNameError": "Enter a name for the preset.",
+  "equalizerSavePresetConfirm": "Save",
   "preferredStationTitle": "Preferred station",
   "preferredStationDescription": "Preselected for new alarms and available for quick playback.",
   "preferredStationNoStationsTitle": "No stations available yet",

lib/l10n/app_es.arb

@@ -95,6 +95,17 @@
   "equalizerPerStationTitle": "Usar EQ propio para esta favorita",
   "equalizerPerStationActive": "Activo para {stationName}",
   "equalizerPerStationMain": "Usando EQ principal para {stationName}",
+  "equalizerBaseExplainer": "Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.",
+  "equalizerActiveOutputLabel": "Salida activa",
+  "equalizerActiveOutputDefault": "El altavoz de este dispositivo",
+  "equalizerStationsWithOwnEqTitle": "Emisoras con ajuste propio",
+  "equalizerStationsWithOwnEqSubtitle": "Ignoran este ecualizador base",
+  "equalizerStationsWithOwnEqEmpty": "Ninguna emisora tiene ajuste propio todavía.",
+  "equalizerSaveAsPresetAction": "Guardar como preset",
+  "equalizerSavePresetDialogTitle": "Guardar como preset",
+  "equalizerSavePresetNameLabel": "Nombre del preset",
+  "equalizerSavePresetEmptyNameError": "Ingresá un nombre para el preset.",
+  "equalizerSavePresetConfirm": "Guardar",
   "preferredStationTitle": "Emisora preferida",
   "preferredStationDescription": "Se preselecciona al crear alarmas y puede iniciarse como reproducción rápida.",
   "preferredStationNoStationsTitle": "Todavía no hay emisoras disponibles",

lib/l10n/gen/app_localizations.dart

@@ -496,6 +496,72 @@ abstract class AppLocalizations {
   /// **'Usando EQ principal para {stationName}'**
   String equalizerPerStationMain(Object stationName);
 
+  /// No description provided for @equalizerBaseExplainer.
+  ///
+  /// In es, this message translates to:
+  /// **'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.'**
+  String get equalizerBaseExplainer;
+
+  /// No description provided for @equalizerActiveOutputLabel.
+  ///
+  /// In es, this message translates to:
+  /// **'Salida activa'**
+  String get equalizerActiveOutputLabel;
+
+  /// No description provided for @equalizerActiveOutputDefault.
+  ///
+  /// In es, this message translates to:
+  /// **'El altavoz de este dispositivo'**
+  String get equalizerActiveOutputDefault;
+
+  /// No description provided for @equalizerStationsWithOwnEqTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Emisoras con ajuste propio'**
+  String get equalizerStationsWithOwnEqTitle;
+
+  /// No description provided for @equalizerStationsWithOwnEqSubtitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Ignoran este ecualizador base'**
+  String get equalizerStationsWithOwnEqSubtitle;
+
+  /// No description provided for @equalizerStationsWithOwnEqEmpty.
+  ///
+  /// In es, this message translates to:
+  /// **'Ninguna emisora tiene ajuste propio todavía.'**
+  String get equalizerStationsWithOwnEqEmpty;
+
+  /// No description provided for @equalizerSaveAsPresetAction.
+  ///
+  /// In es, this message translates to:
+  /// **'Guardar como preset'**
+  String get equalizerSaveAsPresetAction;
+
+  /// No description provided for @equalizerSavePresetDialogTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Guardar como preset'**
+  String get equalizerSavePresetDialogTitle;
+
+  /// No description provided for @equalizerSavePresetNameLabel.
+  ///
+  /// In es, this message translates to:
+  /// **'Nombre del preset'**
+  String get equalizerSavePresetNameLabel;
+
+  /// No description provided for @equalizerSavePresetEmptyNameError.
+  ///
+  /// In es, this message translates to:
+  /// **'Ingresá un nombre para el preset.'**
+  String get equalizerSavePresetEmptyNameError;
+
+  /// No description provided for @equalizerSavePresetConfirm.
+  ///
+  /// In es, this message translates to:
+  /// **'Guardar'**
+  String get equalizerSavePresetConfirm;
+
   /// No description provided for @preferredStationTitle.
   ///
   /// In es, this message translates to:

lib/l10n/gen/app_localizations_ar.dart

@@ -223,6 +223,43 @@ class AppLocalizationsAr extends AppLocalizations {
     return 'استخدام المعادل الرئيسي لـ $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'المحطة المفضلة';
 

lib/l10n/gen/app_localizations_bn.dart

@@ -226,6 +226,43 @@ class AppLocalizationsBn extends AppLocalizations {
     return '$stationName-এর জন্য মূল ইকুয়ালাইজার ব্যবহার করা হচ্ছে';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'পছন্দের স্টেশন';
 

lib/l10n/gen/app_localizations_de.dart

@@ -226,6 +226,43 @@ class AppLocalizationsDe extends AppLocalizations {
     return 'Haupt-EQ für $stationName wird verwendet';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'Bevorzugter Sender';
 

lib/l10n/gen/app_localizations_en.dart

@@ -224,6 +224,42 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Using main EQ for $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'This is the base equalizer: it applies to every station without its own setting. A station\'s own EQ is set from its own playback screen and overrides this one.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Active output';
+
+  @override
+  String get equalizerActiveOutputDefault => 'This device\'s speaker';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Stations with their own EQ';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle => 'Ignore this base equalizer';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'No stations have their own EQ yet.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Save as preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Save as preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Preset name';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Enter a name for the preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Save';
+
   @override
   String get preferredStationTitle => 'Preferred station';
 

lib/l10n/gen/app_localizations_es.dart

@@ -225,6 +225,43 @@ class AppLocalizationsEs extends AppLocalizations {
     return 'Usando EQ principal para $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'Emisora preferida';
 

lib/l10n/gen/app_localizations_fr.dart

@@ -227,6 +227,43 @@ class AppLocalizationsFr extends AppLocalizations {
     return 'EQ principal utilisé pour $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'Station préférée';
 

lib/l10n/gen/app_localizations_hi.dart

@@ -225,6 +225,43 @@ class AppLocalizationsHi extends AppLocalizations {
     return '$stationName के लिए मुख्य EQ इस्तेमाल हो रहा है';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'पसंदीदा स्टेशन';
 

lib/l10n/gen/app_localizations_id.dart

@@ -225,6 +225,43 @@ class AppLocalizationsId extends AppLocalizations {
     return 'Menggunakan EQ utama untuk $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'Stasiun pilihan';
 

lib/l10n/gen/app_localizations_it.dart

@@ -225,6 +225,43 @@ class AppLocalizationsIt extends AppLocalizations {
     return 'EQ principale in uso per $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'Emittente preferita';
 

lib/l10n/gen/app_localizations_ja.dart

@@ -217,6 +217,43 @@ class AppLocalizationsJa extends AppLocalizations {
     return '$stationName でメインEQを使用中';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => '優先局';
 

lib/l10n/gen/app_localizations_pt.dart

@@ -224,6 +224,43 @@ class AppLocalizationsPt extends AppLocalizations {
     return 'Usando o EQ principal para $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'Estação preferida';
 

lib/l10n/gen/app_localizations_ru.dart

@@ -226,6 +226,43 @@ class AppLocalizationsRu extends AppLocalizations {
     return 'Используется основной EQ для $stationName';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => 'Предпочитаемая станция';
 

lib/l10n/gen/app_localizations_zh.dart

@@ -216,6 +216,43 @@ class AppLocalizationsZh extends AppLocalizations {
     return '正在为 $stationName 使用主均衡器';
   }
 
+  @override
+  String get equalizerBaseExplainer =>
+      'Este es el ecualizador base: se aplica a todas las emisoras que no tengan un ajuste propio. El de una emisora concreta se define desde su propia reproducción y manda sobre este.';
+
+  @override
+  String get equalizerActiveOutputLabel => 'Salida activa';
+
+  @override
+  String get equalizerActiveOutputDefault => 'El altavoz de este dispositivo';
+
+  @override
+  String get equalizerStationsWithOwnEqTitle => 'Emisoras con ajuste propio';
+
+  @override
+  String get equalizerStationsWithOwnEqSubtitle =>
+      'Ignoran este ecualizador base';
+
+  @override
+  String get equalizerStationsWithOwnEqEmpty =>
+      'Ninguna emisora tiene ajuste propio todavía.';
+
+  @override
+  String get equalizerSaveAsPresetAction => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetDialogTitle => 'Guardar como preset';
+
+  @override
+  String get equalizerSavePresetNameLabel => 'Nombre del preset';
+
+  @override
+  String get equalizerSavePresetEmptyNameError =>
+      'Ingresá un nombre para el preset.';
+
+  @override
+  String get equalizerSavePresetConfirm => 'Guardar';
+
   @override
   String get preferredStationTitle => '首选电台';
 

lib/pantallas/ajustes/pantalla_ajustes_ecualizador.dart

@@ -1,9 +1,12 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 import '../../estado/estado_ecualizador.dart';
 import '../../estado/estado_radio.dart';
 import '../../l10n/gen/app_localizations.dart';
+import '../../tema/pluriwave_theme.dart';
 import '../../widgets/ecualizador_widget.dart';
 import '../../widgets/pluri_glass_surface.dart';
 import '../../widgets/pluri_layout.dart';
@@ -15,8 +18,10 @@ import '../../widgets/pluri_push_scaffold.dart';
 /// [PluriPushScaffold] now carries the title and the very next row already
 /// shows the same active/disabled state.
 ///
-/// This body is a placeholder pending WU13's restyle (ADR-3's own component
+/// WU13 (design ADR-5) restyled [EcualizadorWidget] itself and added the
-/// inventory: "body rewritten by WU13").
+/// base-vs-per-station explainer, the "Salida activa" summary row, the
+/// "Emisoras con ajuste propio" drill-down, and the "Guardar como preset"
+/// custom-preset flow — see `_CuerpoEcualizador` below.
 class PantallaAjustesEcualizador extends StatelessWidget {
   const PantallaAjustesEcualizador({super.key});
 
@@ -30,13 +35,32 @@ class PantallaAjustesEcualizador extends StatelessWidget {
   );
 }
 
-class _CuerpoEcualizador extends StatelessWidget {
+class _CuerpoEcualizador extends StatefulWidget {
   const _CuerpoEcualizador();
 
+  @override
+  State<_CuerpoEcualizador> createState() => _CuerpoEcualizadorState();
+}
+
+class _CuerpoEcualizadorState extends State<_CuerpoEcualizador> {
+  @override
+  void initState() {
+    super.initState();
+    final eq = context.read<EstadoEcualizador>();
+    // Fire-and-forget, mirroring the established
+    // `pantalla_ajustes_salida_audio.dart` pattern: both calls are
+    // genuinely async (a SharedPreferences read / a native re-query), so
+    // their completion never lands inside THIS build — no
+    // "setState() during build" risk.
+    unawaited(eq.cargarPresetsPersonalizados());
+    unawaited(eq.refrescarDispositivoActual());
+  }
+
   @override
   Widget build(BuildContext context) {
     // EQ state comes from EstadoEcualizador (S4-R1/S4-R5); EstadoRadio is
-    // only consulted for the current station + favorite flag.
+    // only consulted for the current station + favorite flag and for
+    // resolving station names in the "ajuste propio" drill-down.
     return Consumer2<EstadoRadio, EstadoEcualizador>(
       builder: (ctx, estado, eq, _) {
         final disponible = eq.disponible;
@@ -77,16 +101,34 @@ class _CuerpoEcualizador extends StatelessWidget {
                           eq.cambiarModoEmisoraActual(usarPropio: usarPropio),
                 ),
               ],
+              const SizedBox(height: 12),
+              _BannerExplicacionBase(l10n: l10n),
               const SizedBox(height: 8),
+              _FilaSalidaActiva(eq: eq, l10n: l10n),
+              const SizedBox(height: 4),
+              _FilaEmisorasConAjustePropio(eq: eq, estado: estado, l10n: l10n),
+              const SizedBox(height: 12),
               PresetsEcualizadorWidget(
                 presetActual: eq.presetActual,
+                personalizados: eq.presetsPersonalizados,
                 onSeleccionar: (p) => eq.cambiarPreset(p),
               ),
               const SizedBox(height: 12),
               EcualizadorWidget(
                 preset: eq.presetActual,
+                habilitado: eq.activo,
                 onCambio: (p) => eq.cambiarPreset(p),
               ),
+              const SizedBox(height: 12),
+              Align(
+                alignment: Alignment.centerRight,
+                child: TextButton.icon(
+                  key: const Key('eq-save-preset-action'),
+                  onPressed: () => _abrirDialogoGuardarPreset(context, eq),
+                  icon: const Icon(Icons.bookmark_add_outlined, size: 20),
+                  label: Text(l10n.equalizerSaveAsPresetAction),
+                ),
+              ),
             ],
           ),
         );
@@ -94,3 +136,281 @@ class _CuerpoEcualizador extends StatelessWidget {
     );
   }
 }
+
+Future<void> _abrirDialogoGuardarPreset(
+  BuildContext context,
+  EstadoEcualizador eq,
+) {
+  return showDialog<void>(
+    context: context,
+    builder: (_) => _DialogoGuardarPreset(eq: eq),
+  );
+}
+
+/// Base-vs-per-station explainer (spec `eq-custom-presets` "Base-vs-Per-
+/// Station Explainer Preserved"): always visible, distinguishing the base
+/// (global/device) EQ this screen edits from a station's own override.
+class _BannerExplicacionBase extends StatelessWidget {
+  const _BannerExplicacionBase({required this.l10n});
+
+  final AppLocalizations l10n;
+
+  @override
+  Widget build(BuildContext context) {
+    final tokens = context.pluriTokens;
+    return Container(
+      key: const Key('eq-base-explainer-banner'),
+      padding: const EdgeInsets.all(14),
+      decoration: BoxDecoration(
+        color: tokens.liveGreen.withValues(alpha: 0.09),
+        borderRadius: BorderRadius.circular(tokens.radiusSm),
+        border: Border.all(color: tokens.liveGreen.withValues(alpha: 0.26)),
+      ),
+      child: Row(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Icon(Icons.info_outline_rounded, size: 20, color: tokens.liveGreen),
+          const SizedBox(width: 11),
+          Expanded(
+            child: Text(
+              l10n.equalizerBaseExplainer,
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+/// "Salida activa" row (spec `eq-custom-presets` "Active Output Surfaced on
+/// the Main Screen"): surfaced here instead of only inside the Advanced
+/// (multi-device) screen, and kept live via the SAME `notifyListeners()`
+/// calls `_onDispositivoCambiado` already fires — no new plumbing needed
+/// beyond reading `dispositivoActualId` here.
+class _FilaSalidaActiva extends StatelessWidget {
+  const _FilaSalidaActiva({required this.eq, required this.l10n});
+
+  final EstadoEcualizador eq;
+  final AppLocalizations l10n;
+
+  @override
+  Widget build(BuildContext context) {
+    final deviceId = eq.dispositivoActualId;
+    final nombre =
+        deviceId == null
+            ? l10n.equalizerActiveOutputDefault
+            : eq.nombreVisible(deviceId, eq.nombrePlataforma(deviceId));
+
+    return Padding(
+      key: const Key('eq-active-output-row'),
+      padding: const EdgeInsets.symmetric(vertical: 4),
+      child: Row(
+        children: [
+          const Icon(Icons.speaker_group_rounded, size: 20),
+          const SizedBox(width: 12),
+          Expanded(
+            child: Text(
+              l10n.equalizerActiveOutputLabel,
+              style: Theme.of(context).textTheme.bodyMedium,
+            ),
+          ),
+          Flexible(
+            child: Text(
+              nombre,
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+              textAlign: TextAlign.end,
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+/// "Emisoras con ajuste propio" drill-down row (spec `eq-custom-presets`
+/// "Stations-With-Own-EQ Drill-Down"): sourced from the existing
+/// `presetsPorEmisora` map, no new state.
+class _FilaEmisorasConAjustePropio extends StatelessWidget {
+  const _FilaEmisorasConAjustePropio({
+    required this.eq,
+    required this.estado,
+    required this.l10n,
+  });
+
+  final EstadoEcualizador eq;
+  final EstadoRadio estado;
+  final AppLocalizations l10n;
+
+  @override
+  Widget build(BuildContext context) {
+    final uuids = eq.presetsPorEmisora.keys.toList();
+    return Material(
+      type: MaterialType.transparency,
+      child: InkWell(
+        key: const Key('eq-stations-own-eq-row'),
+        borderRadius: BorderRadius.circular(context.pluriTokens.radiusSm),
+        onTap:
+            () => PluriPushScaffold.push(
+              context,
+              (_) => _PantallaEmisorasConAjustePropio(
+                uuids: uuids,
+                nombrePorUuid: (uuid) => _resolverNombreEmisora(estado, uuid),
+              ),
+            ),
+        child: Padding(
+          padding: const EdgeInsets.symmetric(vertical: 8),
+          child: Row(
+            children: [
+              const Icon(Icons.tune_rounded, size: 20),
+              const SizedBox(width: 12),
+              Expanded(
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    Text(
+                      l10n.equalizerStationsWithOwnEqTitle,
+                      style: Theme.of(context).textTheme.bodyMedium,
+                    ),
+                    Text(
+                      l10n.equalizerStationsWithOwnEqSubtitle,
+                      style: Theme.of(context).textTheme.bodySmall,
+                    ),
+                  ],
+                ),
+              ),
+              Text(
+                key: const Key('eq-stations-own-eq-count'),
+                '${uuids.length}',
+                style: Theme.of(context).textTheme.bodySmall,
+              ),
+              const SizedBox(width: 4),
+              const Icon(Icons.chevron_right_rounded, size: 20),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+/// Resolves a station uuid to its display name via [EstadoRadio.listaFavoritos]
+/// (the only local, synchronous list of known stations) — falls back to the
+/// raw uuid for a station that has its own EQ but is not (or no longer) a
+/// favorite, e.g. one set from the player's per-station EQ sheet (WU14).
+String _resolverNombreEmisora(EstadoRadio estado, String uuid) {
+  for (final emisora in estado.listaFavoritos) {
+    if (emisora.uuid == uuid) return emisora.nombre;
+  }
+  return uuid;
+}
+
+/// Destination screen for the drill-down row above.
+class _PantallaEmisorasConAjustePropio extends StatelessWidget {
+  const _PantallaEmisorasConAjustePropio({
+    required this.uuids,
+    required this.nombrePorUuid,
+  });
+
+  final List<String> uuids;
+  final String Function(String uuid) nombrePorUuid;
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    return PluriPushScaffold(
+      title: l10n.equalizerStationsWithOwnEqTitle,
+      body:
+          uuids.isEmpty
+              ? Center(child: Text(l10n.equalizerStationsWithOwnEqEmpty))
+              : ListView.separated(
+                padding: PluriLayout.pageContentPadding,
+                itemCount: uuids.length,
+                separatorBuilder: (_, __) => const SizedBox(height: 4),
+                itemBuilder: (ctx, i) {
+                  final uuid = uuids[i];
+                  return Padding(
+                    padding: const EdgeInsets.symmetric(vertical: 8),
+                    child: Row(
+                      children: [
+                        const Icon(Icons.radio_rounded, size: 20),
+                        const SizedBox(width: 12),
+                        Expanded(child: Text(nombrePorUuid(uuid))),
+                      ],
+                    ),
+                  );
+                },
+              ),
+    );
+  }
+}
+
+/// "Guardar como preset" dialog (spec `eq-custom-presets` "Custom Preset
+/// Save" / "Custom Preset Naming Validates Non-Empty Input").
+class _DialogoGuardarPreset extends StatefulWidget {
+  const _DialogoGuardarPreset({required this.eq});
+
+  final EstadoEcualizador eq;
+
+  @override
+  State<_DialogoGuardarPreset> createState() => _DialogoGuardarPresetState();
+}
+
+class _DialogoGuardarPresetState extends State<_DialogoGuardarPreset> {
+  late final TextEditingController _nombreCtrl;
+  String? _error;
+
+  @override
+  void initState() {
+    super.initState();
+    _nombreCtrl = TextEditingController();
+  }
+
+  @override
+  void dispose() {
+    _nombreCtrl.dispose();
+    super.dispose();
+  }
+
+  Future<void> _confirmar() async {
+    final guardado = await widget.eq.guardarPresetPersonalizado(
+      _nombreCtrl.text,
+    );
+    if (!mounted) return;
+    if (!guardado) {
+      setState(
+        () =>
+            _error =
+                AppLocalizations.of(context).equalizerSavePresetEmptyNameError,
+      );
+      return;
+    }
+    Navigator.of(context).pop();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    return AlertDialog(
+      title: Text(l10n.equalizerSavePresetDialogTitle),
+      content: TextField(
+        key: const Key('eq-save-preset-name-field'),
+        controller: _nombreCtrl,
+        autofocus: true,
+        decoration: InputDecoration(
+          labelText: l10n.equalizerSavePresetNameLabel,
+          errorText: _error,
+        ),
+      ),
+      actions: [
+        FilledButton(
+          key: const Key('eq-save-preset-confirm-button'),
+          onPressed: _confirmar,
+          child: Text(l10n.equalizerSavePresetConfirm),
+        ),
+      ],
+    );
+  }
+}

lib/servicios/servicio_presets_personalizados.dart

@@ -0,0 +1,88 @@
+import 'dart:convert';
+
+import 'package:shared_preferences/shared_preferences.dart';
+
+import '../modelos/preset_ecualizador.dart';
+import 'persistencia_tolerante.dart';
+
+/// Persistence for USER-NAMED custom EQ presets (design ADR-5 hazard box,
+/// `eq-custom-presets` spec — "Custom Preset Save").
+///
+/// Deliberately its OWN file and OWN SharedPreferences key
+/// (`eq_custom_presets_v1`), never folded into [ServicioEcualizador]: that
+/// file has an empty-`git diff` success criterion for this change, so
+/// nothing custom-preset-related may be added there. A custom preset is
+/// just a [PresetEcualizador] with a user-supplied `nombre` — the model
+/// itself needs no change (`toJson`/`desdeJson` already exist).
+class ServicioPresetsPersonalizados {
+  ServicioPresetsPersonalizados({SharedPreferences? prefs}) : _prefs = prefs;
+
+  static const _keyPresetsPersonalizados = 'eq_custom_presets_v1';
+
+  final SharedPreferences? _prefs;
+
+  Future<SharedPreferences> _resolverPrefs() async =>
+      _prefs ?? SharedPreferences.getInstance();
+
+  /// Returns every saved custom preset, in save order.
+  Future<List<PresetEcualizador>> listar() async {
+    final prefs = await _resolverPrefs();
+    return _leer(prefs);
+  }
+
+  /// Saves [preset] under its own name. A preset already saved under the
+  /// same name is replaced (last write wins) rather than duplicated.
+  Future<void> guardar(PresetEcualizador preset) async {
+    final prefs = await _resolverPrefs();
+    final actuales =
+        _leer(prefs)
+          ..removeWhere((p) => p.nombre == preset.nombre)
+          ..add(preset);
+    await _guardarTodos(prefs, actuales);
+  }
+
+  /// Removes the custom preset named [nombre], if present. A safe no-op
+  /// when no preset with that name exists.
+  Future<void> eliminar(String nombre) async {
+    final prefs = await _resolverPrefs();
+    final actuales = _leer(prefs)..removeWhere((p) => p.nombre == nombre);
+    await _guardarTodos(prefs, actuales);
+  }
+
+  /// Reads the persisted list with per-entry tolerance
+  /// (persistence-resilience D1/D6, same shared helper `ServicioEcualizador`
+  /// uses): an entry that fails to parse is skipped and logged, its
+  /// siblings survive. A top-level decode failure degrades to an empty
+  /// list (also logged) — custom presets are explicit-only user writes and
+  /// trivially re-creatable, so there is no flag/quarantine here, matching
+  /// `ServicioEcualizador`'s own documented D6 asymmetry vs. Alarms/Stations.
+  List<PresetEcualizador> _leer(SharedPreferences prefs) {
+    final raw = prefs.getString(_keyPresetsPersonalizados);
+    if (raw == null || raw.isEmpty) return [];
+    try {
+      final data = jsonDecode(raw) as List<dynamic>;
+      final resultado = parseListaTolerante<PresetEcualizador>(
+        data,
+        (entrada) => PresetEcualizador.desdeJson(entrada),
+        subsistema: 'presets_personalizados',
+        coleccion: _keyPresetsPersonalizados,
+      );
+      return resultado.validas;
+    } catch (e) {
+      registrarSaltoPersistencia(
+        subsistema: 'presets_personalizados',
+        detalle: _keyPresetsPersonalizados,
+        razon: e.toString(),
+      );
+      return [];
+    }
+  }
+
+  Future<void> _guardarTodos(
+    SharedPreferences prefs,
+    List<PresetEcualizador> presets,
+  ) async {
+    final serializado = presets.map((p) => p.toJson()).toList();
+    await prefs.setString(_keyPresetsPersonalizados, jsonEncode(serializado));
+  }
+}

lib/widgets/ecualizador_widget.dart

@@ -9,10 +9,16 @@ class EcualizadorWidget extends StatefulWidget {
   final PresetEcualizador preset;
   final void Function(PresetEcualizador) onCambio;
 
+  /// Design ADR-5: greys and disables every slider when the equalizer
+  /// itself is off, instead of leaving fully-interactive controls that
+  /// silently do nothing.
+  final bool habilitado;
+
   const EcualizadorWidget({
     super.key,
     required this.preset,
     required this.onCambio,
+    this.habilitado = true,
   });
 
   @override
@@ -50,91 +56,92 @@ class _EcualizadorWidgetState extends State<EcualizadorWidget> {
     final tokens = context.pluriTokens;
     final l10n = AppLocalizations.of(context);
 
+    // Design ADR-5: the title + preset Chip row that used to live here is
+    // gone — the pushed screen's own 56px header carries the title now, and
+    // the preset chip ROW (a different, still-reusable widget,
+    // [PresetsEcualizadorWidget] below) is rendered by the caller alongside
+    // this widget instead of being duplicated inside it.
     return PluriGlassSurface(
       borderRadius: BorderRadius.circular(tokens.radiusLg),
       padding: const EdgeInsets.all(16),
-      child: Column(
+      child: Row(
-        crossAxisAlignment: CrossAxisAlignment.stretch,
+        crossAxisAlignment: CrossAxisAlignment.end,
+        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
         children: [
-          Row(
+          for (int i = 0; i < 5; i++)
-            children: [
+            Expanded(
-              Text(
+              child: AnimatedOpacity(
-                l10n.equalizerTitle,
+                duration: const Duration(milliseconds: 150),
-                style: theme.textTheme.titleMedium?.copyWith(
+                opacity: widget.habilitado ? 1.0 : 0.4,
-                  fontWeight: FontWeight.w700,
+                child: Card(
-                ),
+                  color: tokens.listSurface.withValues(alpha: 0.6),
-              ),
+                  margin: const EdgeInsets.symmetric(horizontal: 4),
-              const Spacer(),
+                  shape: RoundedRectangleBorder(
-              Chip(
+                    borderRadius: BorderRadius.circular(tokens.radiusSm),
-                label: Text(
+                  ),
-                  _nombrePreset(l10n, widget.preset.nombre),
+                  child: Padding(
-                  style: theme.textTheme.labelMedium,
+                    padding: const EdgeInsets.symmetric(
-                ),
+                      vertical: 10,
-                backgroundColor: theme.colorScheme.secondaryContainer
+                      horizontal: 4,
-                    .withValues(alpha: 0.75),
-              ),
-            ],
-          ),
-          const SizedBox(height: 14),
-          Row(
-            crossAxisAlignment: CrossAxisAlignment.end,
-            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
-            children: [
-              for (int i = 0; i < 5; i++)
-                Expanded(
-                  child: Card(
-                    color: theme.colorScheme.surfaceContainerHighest.withValues(
-                      alpha: 0.35,
                     ),
-                    margin: const EdgeInsets.symmetric(horizontal: 4),
+                    child: Column(
-                    shape: RoundedRectangleBorder(
+                      children: [
-                      borderRadius: BorderRadius.circular(14),
+                        SizedBox(
-                    ),
+                          height: 152,
-                    child: Padding(
+                          child: Semantics(
-                      padding: const EdgeInsets.symmetric(
+                            slider: true,
-                        vertical: 8,
+                            enabled: widget.habilitado,
-                        horizontal: 4,
+                            label: l10n.equalizerBandLabel(_etiquetas[i]),
-                      ),
+                            value: l10n.equalizerBandValue(
-                      child: Column(
+                              _bandas[i].toStringAsFixed(1),
-                        children: [
+                            ),
-                          SizedBox(
+                            child: RotatedBox(
-                            height: 152,
+                              quarterTurns: 3,
-                            child: Semantics(
+                              child: SliderTheme(
-                              slider: true,
+                                data: SliderTheme.of(context).copyWith(
-                              label: l10n.equalizerBandLabel(_etiquetas[i]),
+                                  trackHeight: 5,
-                              value: l10n.equalizerBandValue(
+                                  activeTrackColor: tokens.liveGreen,
-                                _bandas[i].toStringAsFixed(1),
+                                  thumbColor: tokens.liveGreen,
-                              ),
+                                  inactiveTrackColor:
-                              child: RotatedBox(
+                                      theme.colorScheme.surfaceContainerHighest,
-                                quarterTurns: 3,
+                                  overlayColor: tokens.liveGreen.withValues(
+                                    alpha: 0.15,
+                                  ),
+                                ),
                                 child: Slider(
                                   value: _bandas[i],
                                   min: -12.0,
                                   max: 12.0,
                                   divisions: 24,
-                                  onChanged: (v) => _actualizarBanda(i, v),
+                                  onChanged:
+                                      widget.habilitado
+                                          ? (v) => _actualizarBanda(i, v)
+                                          : null,
                                 ),
                               ),
                             ),
                           ),
-                          Text(
+                        ),
-                            '${_bandas[i].toStringAsFixed(1)}dB',
+                        Text(
-                            style: theme.textTheme.labelSmall,
+                          '${_bandas[i].toStringAsFixed(1)}dB',
+                          style: theme.textTheme.labelSmall?.copyWith(
+                            color: tokens.liveGreen,
+                            fontWeight: FontWeight.w700,
                           ),
-                          Text(
+                        ),
-                            _etiquetas[i],
+                        Text(
-                            style: theme.textTheme.bodySmall?.copyWith(
+                          _etiquetas[i],
-                              color: theme.colorScheme.onSurfaceVariant,
+                          style: theme.textTheme.bodySmall?.copyWith(
-                            ),
+                            color: theme.colorScheme.onSurfaceVariant,
-                            textAlign: TextAlign.center,
                           ),
-                        ],
+                          textAlign: TextAlign.center,
-                      ),
+                        ),
+                      ],
                     ),
                   ),
                 ),
-            ],
+              ),
-          ),
+            ),
         ],
       ),
     );
@@ -158,21 +165,31 @@ class PresetsEcualizadorWidget extends StatelessWidget {
   final PresetEcualizador presetActual;
   final void Function(PresetEcualizador) onSeleccionar;
 
+  /// User-saved custom presets (WU13, `eq-custom-presets` spec), appended
+  /// after the 6 fixed ones. Additive-only parameter — defaults to empty so
+  /// this stays the same widget, not a new one (design ADR-5: "stays
+  /// as-is" means no restyle, not that it can never gain new data to show).
+  /// `_nombrePreset`'s default case already falls through to the raw name,
+  /// so a custom preset's chip label needs no special-casing here.
+  final List<PresetEcualizador> personalizados;
+
   const PresetsEcualizadorWidget({
     super.key,
     required this.presetActual,
     required this.onSeleccionar,
+    this.personalizados = const [],
   });
 
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
     final l10n = AppLocalizations.of(context);
+    final todos = [...PresetEcualizador.presets, ...personalizados];
     return Wrap(
       spacing: 8,
       runSpacing: 6,
       children:
-          PresetEcualizador.presets.map((p) {
+          todos.map((p) {
             final selected = p.nombre == presetActual.nombre;
             return ChoiceChip(
               label: Text(_nombrePreset(l10n, p.nombre)),

openspec/changes/rediseno-funcional/tasks.md

@@ -51,7 +51,7 @@
 | 9 | `feat(vacaciones): add vacation range manager screen` | 8 | 350-450 | Medium | Monitor |
 | 10 | `feat(alarmas): rewrite alarm editor with inline time widget` | 8 | 500-650 | High | **Yes — indivisible new widget**‡ |
 | 11 | `feat(alarma-sonando): restyle ringing screen, drop live countdown label` | 1 | 200-300 | Low (safety-critical review attention: High) | No |
-| 13 | `feat(eq): restyle equalizer screen and add custom presets` | 3a | 400-550 | Medium-High | Monitor |
+| 13 | `feat(eq): restyle equalizer screen and add custom presets` | 3a | ~~400-550~~ → **REALIZED: 1,871** (1,793+ / 78-, 25 files) | Medium-High | **Yes — retroactive, see WU13 section** |
 | 14 | `feat(reproductor): restructure full player with tool-tray and EQ sheet` | 13 | 450-600 | Medium-High | Monitor |
 | 15 | `feat(grabaciones): add recordings library screen` | 3b | ~~300-400~~ → **REALIZED: 1,767** (1,767+ / 0-, 22 files) | Medium | Monitor§ |
 | 15b | `fix(grabaciones): wire the recordings library into Settings navigation` | 15 | 60-100 | Low | No |
@@ -735,32 +735,67 @@ Stations-With-Own-EQ Drill-Down, Base-vs-Per-Station Explainer Preserved, Active
 > **Hazard, restated: persistence for custom presets must NOT go in `servicio_ecualizador.dart`.** That file has an
 > empty-`git diff` success criterion.
 
-- [ ] 13.1 RED — the Ecualizador screen renders exactly **5** vertical sliders (regression guard — reject any
+- [x] 13.1 RED — the Ecualizador screen renders exactly **5** vertical sliders (regression guard — reject any
-       future 7-slider change on sight).
+       future 7-slider change on sight). **Corrected at apply time**: named test file `ecualizador_widget_test.dart`
-- [ ] 13.2 RED — `servicio_presets_personalizados_test.dart`: save/list/delete round-trip for a named custom preset
+       did not exist before this commit (`ecualizador_widget.dart` had zero coverage) — created new, plus the
+       screen-level assertion in `pantalla_ajustes_ecualizador_test.dart` (the spec scenario's own GIVEN is "the
+       Ecualizador settings screen").
+- [x] 13.2 RED — `servicio_presets_personalizados_test.dart`: save/list/delete round-trip for a named custom preset
        via its **own** SharedPreferences key `eq_custom_presets_v1`.
-- [ ] 13.3 RED — submitting an empty/whitespace-only preset name shows a validation message and persists nothing.
+- [x] 13.3 RED — submitting an empty/whitespace-only preset name shows a validation message and persists nothing.
-- [ ] 13.4 RED — the "Emisoras con ajuste propio" drill-down lists exactly the stations present in
+       Covered at both the state layer (new `estado_ecualizador_presets_personalizados_test.dart` — see 13.7's note)
+       and the UI layer (`pantalla_ajustes_ecualizador_test.dart`'s "Guardar como preset" dialog scenarios).
+- [x] 13.4 RED — the "Emisoras con ajuste propio" drill-down lists exactly the stations present in
        `presetsPorEmisora`.
-- [ ] 13.5 RED — the "Salida activa" row is visible on the main screen (not only Advanced) and updates on a
+- [x] 13.5 RED — the "Salida activa" row is visible on the main screen (not only Advanced) and updates on a
        simulated device change; the base-vs-per-station explainer banner is visible.
-- [ ] 13.6 GREEN — create `lib/servicios/servicio_presets_personalizados.dart` (**new file**, own SharedPreferences
+- [x] 13.6 GREEN — create `lib/servicios/servicio_presets_personalizados.dart` (**new file**, own SharedPreferences
        key). **Do NOT add any member to `servicio_ecualizador.dart`.** `lib/modelos/preset_ecualizador.dart` stays
        unchanged — a user preset is a `PresetEcualizador` with a user-supplied `nombre`; `toJson`/`desdeJson`
        already exist.
-- [ ] 13.7 GREEN — extend `EstadoEcualizador` with `presetsPersonalizados`, `guardarPresetPersonalizado(nombre)`,
+- [x] 13.7 GREEN — extend `EstadoEcualizador` with `presetsPersonalizados`, `guardarPresetPersonalizado(nombre)`,
-       `eliminarPresetPersonalizado(nombre)`, reading/writing only through the new service.
+       `eliminarPresetPersonalizado(nombre)`, reading/writing only through the new service. **Correction found at
-- [ ] 13.8 GREEN — restyle `lib/widgets/ecualizador_widget.dart` in place: strip the internal title + preset chip
+       apply time**: the new custom-preset LOAD (`cargarPresetsPersonalizados()`) is deliberately NOT folded into
-       row (lines 59-77 — the pushed header now carries the title), restyle the 5 `Card`/`RotatedBox`/`Slider`
+       `cargarPersistido()` — that method is exercised ~30 times by `estado_ecualizador_test.dart` (one of the three
-       tiles to the vertical-track look, add the `habilitado` parameter. Keep the `for (int i = 0; i < 5; i++)`
+       protected EQ test files) via Fakes for `servicio`/`dispositivoAudio` ONLY, with zero SharedPreferences
+       awareness anywhere in that file; adding a third always-real-by-default collaborator to it would have
+       introduced real SharedPreferences I/O into every one of those cases. Called explicitly from the screen's
+       `initState` instead (same pattern `refrescarDispositivoActual` already uses). New coverage lives in a NEW
+       file, `test/estado/estado_ecualizador_presets_personalizados_test.dart` — NOT added to
+       `estado_ecualizador_test.dart`, which stays unmodified.
+- [x] 13.8 GREEN — restyle `lib/widgets/ecualizador_widget.dart` in place: strip the internal title + preset chip
+       row (re-verified at the CURRENT lines 59-77 of the pre-WU13 file, not trusted from the design doc's
+       reference), restyle the 5 `Card`/`RotatedBox`/`Slider` tiles to the vertical-track look (token-driven accent
+       colour, `AnimatedOpacity` grey-out), add the `habilitado` parameter (disables + greys every slider).
+       `PresetsEcualizadorWidget` additively widened with an optional `personalizados` list (default empty) so
+       custom presets can join the chip row without a second implementation. Kept the `for (int i = 0; i < 5; i++)`
        loop bound literally `5`.
-- [ ] 13.9 GREEN — build `lib/pantallas/ajustes/pantalla_ajustes_ecualizador.dart` wiring
+- [x] 13.9 GREEN — build out `lib/pantallas/ajustes/pantalla_ajustes_ecualizador.dart` (the WU3a placeholder body)
-       `EstadoEcualizador.presetPrincipal` / `cambiarPresetPrincipal`, surfacing "Salida activa" and the drill-down
+       wiring `EstadoEcualizador.presetPrincipal` / `cambiarPresetPrincipal`, surfacing "Salida activa" (own private
-       row.
+       row, live via the existing device-change `notifyListeners()`) and the drill-down row (own private row +
-- [ ] 13.10 REFACTOR — reviewer check: confirm `git diff` is **empty** for `lib/servicios/servicio_ecualizador.dart`,
+       destination screen, station uuids resolved against `EstadoRadio.listaFavoritos` with a raw-uuid fallback for
+       a non-favorite station). Added the base-vs-per-station explainer banner and the "Guardar como preset" action
+       + dialog (validates via `guardarPresetPersonalizado`, shows an inline `errorText` on empty/whitespace name).
+- [x] 13.10 REFACTOR — reviewer check: confirmed `git diff` is **empty** for `lib/servicios/servicio_ecualizador.dart`,
        `lib/modelos/preset_ecualizador.dart`, and the band-application block at
-       `lib/servicios/servicio_audio.dart:749-762`.
+       `lib/servicios/servicio_audio.dart:749-762` (this WU never touches `servicio_audio.dart` at all).
-- [ ] 13.11 Verify — the three EQ test files pass **unmodified**; exactly 5 sliders render.
+- [x] 13.11 Verify — the three EQ test files (`servicio_ecualizador_test.dart`, `estado_ecualizador_test.dart`,
+       `servicio_audio_eq_reapply_test.dart`) pass **unmodified**; exactly 5 sliders render (component AND screen
+       level). Full suite: 713/713 green (2 skipped, unchanged), up from 682. `flutter analyze`: 1 issue, identical
+       to baseline. Literal-encoding scan: zero hits.
+
+**`size:exception` recorded.** Realized: **1,871 changed lines** (1,793+/78-) across 25 files against the 400-550
+forecast — same "a strict-TDD commit carries its test files, and any ARB touch drags 13 generated files with it"
+pattern as every prior WU (Engram `reference/estimating-strict-tdd-diffs`, id 2514). Breakdown: `lib/` production
+code alone is 628 lines (`pantalla_ajustes_ecualizador.dart` +326, `ecualizador_widget.dart` restyle ~151,
+`estado_ecualizador.dart` +64, new `servicio_presets_personalizados.dart` +87) plus 22 ARB source lines — at the top
+edge of the forecast band by itself given this WU also had to build out a screen body WU3a only stubbed; the 4
+test files (2 new state/service-layer files plus the widget test and the extended screen test) add 675 lines, and
+11 new ARB keys drag in 546 more via the 13 regenerated `lib/l10n/gen/*.dart` files. Justification: the restyle,
+the new persistence service, the state-layer extension and the screen wiring (explainer/salida-activa/drill-down/
+save-flow) are one cohesive vertical slice — WU13 must land as a whole before WU14 can reuse its editor component
+by exact runtime type; splitting further would leave either an unstyled widget with no screen consumer or a screen
+half-wired to a service that doesn't exist yet.
 
 ## WU14 — Reproductor completo + per-station EQ sheet
 

test/estado/estado_ecualizador_presets_personalizados_test.dart

@@ -0,0 +1,161 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/estado/estado_ecualizador.dart';
+import 'package:pluriwave/modelos/preset_ecualizador.dart';
+
+import '../helpers/fakes.dart';
+
+/// WU13 task 13.7 — `EstadoEcualizador`'s new custom-preset members
+/// (`presetsPersonalizados`, `guardarPresetPersonalizado`,
+/// `eliminarPresetPersonalizado`), reading/writing only through the new
+/// `ServicioPresetsPersonalizados` (design ADR-5 hazard box).
+///
+/// **Correction found at apply time, deliberate**: this is a NEW file, not
+/// an addition to `estado_ecualizador_test.dart`. That file is one of the
+/// three EQ test files this change's master guard requires to pass
+/// **unmodified** — it is exercised ~30 times via `cargarPersistido()`
+/// using Fakes for `servicio`/`dispositivoAudio` ONLY, with no
+/// SharedPreferences awareness anywhere in the file. Because of that,
+/// `cargarPersistido()` itself is intentionally left untouched by this WU
+/// (see `cargarPresetsPersonalizados` below) rather than folding a third,
+/// always-real-by-default collaborator into a method exercised by a file
+/// that must never change.
+void main() {
+  EstadoEcualizador buildEq({FakeServicioPresetsPersonalizados? servicio}) {
+    return EstadoEcualizador(
+      audio: FakeServicioAudio(),
+      servicio: FakeServicioEcualizador(),
+      presetsPersonalizadosService:
+          servicio ?? FakeServicioPresetsPersonalizados(),
+    );
+  }
+
+  test('presetsPersonalizados starts empty before loading', () {
+    final eq = buildEq();
+
+    expect(eq.presetsPersonalizados, isEmpty);
+    eq.dispose();
+  });
+
+  test(
+    'cargarPresetsPersonalizados populates presetsPersonalizados from the service',
+    () async {
+      final fakeServicio = FakeServicioPresetsPersonalizados();
+      final preexistente = PresetEcualizador(
+        nombre: 'Ya guardado',
+        bandas: [1, 2, 3, 4, 5],
+      );
+      await fakeServicio.guardar(preexistente);
+      final eq = buildEq(servicio: fakeServicio);
+
+      await eq.cargarPresetsPersonalizados();
+
+      expect(eq.presetsPersonalizados, hasLength(1));
+      expect(eq.presetsPersonalizados.single.nombre, equals('Ya guardado'));
+      eq.dispose();
+    },
+  );
+
+  test(
+    'guardarPresetPersonalizado saves the CURRENT effective preset bands under the given name',
+    () async {
+      final eq = buildEq();
+      await eq.cambiarPreset(PresetEcualizador.jazz);
+
+      final guardado = await eq.guardarPresetPersonalizado('Mi preset');
+
+      expect(guardado, isTrue);
+      expect(eq.presetsPersonalizados, hasLength(1));
+      expect(eq.presetsPersonalizados.single.nombre, equals('Mi preset'));
+      expect(
+        eq.presetsPersonalizados.single.bandas,
+        equals(PresetEcualizador.jazz.bandas),
+      );
+      eq.dispose();
+    },
+  );
+
+  test('guardarPresetPersonalizado notifies listeners on success', () async {
+    final eq = buildEq();
+    var avisos = 0;
+    eq.addListener(() => avisos++);
+
+    await eq.guardarPresetPersonalizado('Preset con nombre');
+
+    expect(avisos, greaterThanOrEqualTo(1));
+    eq.dispose();
+  });
+
+  test(
+    'guardarPresetPersonalizado rejects an empty name: no save, returns false',
+    () async {
+      final eq = buildEq();
+
+      final guardado = await eq.guardarPresetPersonalizado('');
+
+      expect(guardado, isFalse);
+      expect(eq.presetsPersonalizados, isEmpty);
+      eq.dispose();
+    },
+  );
+
+  test(
+    'guardarPresetPersonalizado rejects a whitespace-only name: no save, returns false',
+    () async {
+      final eq = buildEq();
+
+      final guardado = await eq.guardarPresetPersonalizado('   ');
+
+      expect(guardado, isFalse);
+      expect(eq.presetsPersonalizados, isEmpty);
+      eq.dispose();
+    },
+  );
+
+  test(
+    'guardarPresetPersonalizado trims surrounding whitespace from a valid name',
+    () async {
+      final eq = buildEq();
+
+      final guardado = await eq.guardarPresetPersonalizado('  Con espacios  ');
+
+      expect(guardado, isTrue);
+      expect(eq.presetsPersonalizados.single.nombre, equals('Con espacios'));
+      eq.dispose();
+    },
+  );
+
+  test(
+    'eliminarPresetPersonalizado removes a previously saved preset',
+    () async {
+      final eq = buildEq();
+      await eq.guardarPresetPersonalizado('Para borrar');
+      expect(eq.presetsPersonalizados, hasLength(1));
+
+      await eq.eliminarPresetPersonalizado('Para borrar');
+
+      expect(eq.presetsPersonalizados, isEmpty);
+      eq.dispose();
+    },
+  );
+
+  test(
+    'guardarPresetPersonalizado reads/writes only through the injected service '
+    '(never touches ServicioEcualizador)',
+    () async {
+      final fakeEcualizador = FakeServicioEcualizador();
+      final eq = EstadoEcualizador(
+        audio: FakeServicioAudio(),
+        servicio: fakeEcualizador,
+        presetsPersonalizadosService: FakeServicioPresetsPersonalizados(),
+      );
+
+      await eq.guardarPresetPersonalizado('Aislado');
+
+      // ServicioEcualizador's own config is completely untouched by the
+      // custom-preset save — it lives in a separate service (ADR-5 hazard
+      // box), not folded into servicio_ecualizador.dart's persistence.
+      expect(fakeEcualizador.config.porEmisora, isEmpty);
+      eq.dispose();
+    },
+  );
+}

test/helpers/fakes.dart

@@ -11,6 +11,7 @@ import 'package:pluriwave/servicios/servicio_dispositivo_audio.dart';
 import 'package:pluriwave/servicios/servicio_ecualizador.dart';
 import 'package:pluriwave/servicios/servicio_favoritos.dart';
 import 'package:pluriwave/servicios/servicio_grabacion_radio.dart';
+import 'package:pluriwave/servicios/servicio_presets_personalizados.dart';
 import 'package:pluriwave/servicios/servicio_radio.dart';
 
 class FakeServicioAudio extends ServicioAudio {
@@ -477,6 +478,27 @@ class FakeServicioEcualizador extends ServicioEcualizador {
   }
 }
 
+/// In-memory fake for [ServicioPresetsPersonalizados] (WU13). Avoids any
+/// real SharedPreferences I/O in state-layer tests, matching every other
+/// `Fake*` service in this file.
+class FakeServicioPresetsPersonalizados extends ServicioPresetsPersonalizados {
+  final List<PresetEcualizador> _presets = [];
+
+  @override
+  Future<List<PresetEcualizador>> listar() async => List.from(_presets);
+
+  @override
+  Future<void> guardar(PresetEcualizador preset) async {
+    _presets.removeWhere((p) => p.nombre == preset.nombre);
+    _presets.add(preset);
+  }
+
+  @override
+  Future<void> eliminar(String nombre) async {
+    _presets.removeWhere((p) => p.nombre == nombre);
+  }
+}
+
 /// A [ServicioDispositivoAudio] fake that throws on [obtenerDispositivoActual].
 ///
 /// Used to test the graceful-failure path in [EstadoEcualizador.cargarPersistido].

test/pantallas/ajustes/pantalla_ajustes_ecualizador_test.dart

@@ -5,6 +5,9 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:pluriwave/estado/estado_ecualizador.dart';
 import 'package:pluriwave/estado/estado_radio.dart';
 import 'package:pluriwave/l10n/gen/app_localizations.dart';
+import 'package:pluriwave/modelos/dispositivo_audio.dart';
+import 'package:pluriwave/modelos/emisora.dart';
+import 'package:pluriwave/modelos/preset_ecualizador.dart';
 import 'package:pluriwave/pantallas/ajustes/pantalla_ajustes_ecualizador.dart';
 import 'package:pluriwave/widgets/pluri_push_scaffold.dart';
 import 'package:provider/provider.dart';
@@ -17,6 +20,12 @@ import '../../helpers/fakes_alarmas.dart';
 /// a [PluriPushScaffold] and its moved controls (the enable switch) still
 /// respond exactly as they did inside the old `_SeccionEcualizador`.
 ///
+/// WU13 restyled the header away (design ADR-5 — the strip that used to
+/// duplicate "Equalizer" as `EcualizadorWidget`'s own internal title is
+/// gone), added the base-vs-per-station explainer, the "Salida activa"
+/// row, the "Emisoras con ajuste propio" drill-down and the custom-preset
+/// save flow — see the `WU13` group below.
+///
 /// Pre-existing project constraint (see `pantalla_ajustes_test.dart`):
 /// PluriGlassSurface paints a background over ListTile's ink layer (here,
 /// via SwitchListTile), which Flutter flags as a warning-level assertion,
@@ -43,17 +52,33 @@ void main() {
     '${Directory.current.path}/test/fixtures/emisoras_custom_vacio.json',
   );
 
-  Future<EstadoRadio> crearEstado() async {
+  Future<EstadoRadio> crearEstado({
+    Map<String, PresetEcualizador>? porEmisora,
+    FakeServicioDispositivoAudio? dispositivoAudio,
+    bool eqMultiDeviceEnabled = false,
+    List<Emisora> favoritosIniciales = const [],
+  }) async {
+    final favoritos = FakeServicioFavoritos();
+    for (final emisora in favoritosIniciales) {
+      await favoritos.agregar(emisora);
+    }
     final estado = EstadoRadio(
       audio: FakeServicioAudio(),
-      favoritos: FakeServicioFavoritos(),
+      favoritos: favoritos,
       radio: FakeServicioRadio(),
-      servicioEcualizador: FakeServicioEcualizador(),
+      servicioEcualizador: FakeServicioEcualizador(
+        porEmisora: porEmisora,
+        eqMultiDeviceEnabled: eqMultiDeviceEnabled,
+      ),
       servicioGrabacion: FakeServicioGrabacionRadioInactiva(),
+      dispositivoAudio: dispositivoAudio,
       resolverArchivoCustom: archivoCustomVacio,
       iniciarAutomaticamente: false,
     );
     await estado.ecualizador.cargarPersistido();
+    if (favoritosIniciales.isNotEmpty) {
+      await estado.cargarFavoritos();
+    }
     return estado;
   }
 
@@ -82,10 +107,11 @@ void main() {
     await tester.pumpWidget(buildScreen(estado));
     await tester.pumpAndSettle();
 
-    // "Equalizer" also appears inside EcualizadorWidget's own pre-existing
+    // WU13 stripped EcualizadorWidget's own internal "Equalizer" title +
-    // internal header, which WU3a does not touch (ecualizador_widget.dart's
+    // preset Chip row (design ADR-5) — the pushed screen's AppBar is now
-    // header strip is WU13's job per design ADR-5) — so we assert on the
+    // the ONLY place this title renders. Still asserting on the AppBar
-    // AppBar's title specifically rather than a bare text match.
+    // specifically (not a bare text match) keeps this test meaningful even
+    // if a future WU reintroduces a second on-screen occurrence.
     expect(find.byType(PluriPushScaffold), findsOneWidget);
     final appBar = tester.widget<AppBar>(find.byType(AppBar));
     expect((appBar.title as Text).data, equals('Equalizer'));
@@ -107,4 +133,242 @@ void main() {
 
     expect(estado.ecualizador.activo, equals(!before));
   });
+
+  group('WU13 — restyle, custom presets, salida activa, drill-down', () {
+    testWidgets('exactly 5 sliders render on the Ecualizador screen', (
+      tester,
+    ) async {
+      // Spec `eq-custom-presets` "Five-Band Equalizer (Regression Guard)":
+      // GIVEN the user opens the Ecualizador screen THEN exactly 5 sliders
+      // render — asserted here at the SCREEN level (task 13.1's own GIVEN),
+      // in addition to the component-level guard in
+      // `ecualizador_widget_test.dart`.
+      _suppressListTileInkAssertion();
+      final estado = await crearEstado();
+      addTearDown(estado.dispose);
+
+      await tester.pumpWidget(buildScreen(estado));
+      await tester.pumpAndSettle();
+
+      expect(find.byType(Slider), findsNWidgets(5));
+    });
+
+    testWidgets('base-vs-per-station explainer banner is visible', (
+      tester,
+    ) async {
+      _suppressListTileInkAssertion();
+      final estado = await crearEstado();
+      addTearDown(estado.dispose);
+
+      await tester.pumpWidget(buildScreen(estado));
+      await tester.pumpAndSettle();
+
+      expect(find.byKey(const Key('eq-base-explainer-banner')), findsOneWidget);
+    });
+
+    testWidgets(
+      'Salida activa row is visible and shows a default label when no device is tracked',
+      (tester) async {
+        _suppressListTileInkAssertion();
+        final estado = await crearEstado();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await tester.pumpAndSettle();
+
+        expect(find.byKey(const Key('eq-active-output-row')), findsOneWidget);
+        expect(find.text('Active output'), findsOneWidget);
+        expect(
+          find.descendant(
+            of: find.byKey(const Key('eq-active-output-row')),
+            matching: find.text("This device's speaker"),
+          ),
+          findsOneWidget,
+        );
+      },
+    );
+
+    testWidgets('Salida activa row updates on a simulated device change', (
+      tester,
+    ) async {
+      _suppressListTileInkAssertion();
+      final dispositivoAudio = FakeServicioDispositivoAudio();
+      final estado = await crearEstado(
+        dispositivoAudio: dispositivoAudio,
+        eqMultiDeviceEnabled: true,
+      );
+      addTearDown(estado.dispose);
+
+      await tester.pumpWidget(buildScreen(estado));
+      await tester.pumpAndSettle();
+
+      dispositivoAudio.emitirDispositivo(
+        const DispositivoAudio(
+          id: 'bt_a2dp:AA:BB:CC:DD:EE:FF',
+          tipo: TipoDispositivo.bluetoothA2dp,
+          nombre: 'Auriculares BT',
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      expect(
+        find.descendant(
+          of: find.byKey(const Key('eq-active-output-row')),
+          matching: find.text('Auriculares BT'),
+        ),
+        findsOneWidget,
+      );
+    });
+
+    testWidgets(
+      'Emisoras con ajuste propio drill-down lists exactly the overridden stations',
+      (tester) async {
+        _suppressListTileInkAssertion();
+        const favorita = Emisora(
+          uuid: 'uuid-favorita',
+          nombre: 'Radio Favorita',
+          url: 'https://example.com/favorita',
+        );
+        final estado = await crearEstado(
+          porEmisora: {
+            'uuid-favorita': PresetEcualizador.rock,
+            'uuid-no-favorita': PresetEcualizador.jazz,
+          },
+          favoritosIniciales: const [favorita],
+        );
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await tester.pumpAndSettle();
+
+        expect(find.byKey(const Key('eq-stations-own-eq-row')), findsOneWidget);
+        expect(
+          tester
+              .widget<Text>(find.byKey(const Key('eq-stations-own-eq-count')))
+              .data,
+          equals('2'),
+        );
+
+        await tester.tap(find.byKey(const Key('eq-stations-own-eq-row')));
+        await tester.pumpAndSettle();
+
+        // The favorite station resolves to its display name; the other
+        // uuid (never seen among favorites) falls back to the raw uuid —
+        // same fallback chain `nombreVisible` already uses for devices.
+        expect(find.text('Radio Favorita'), findsOneWidget);
+        expect(find.text('uuid-no-favorita'), findsOneWidget);
+      },
+    );
+
+    testWidgets(
+      'drill-down shows an empty state when no station has its own EQ',
+      (tester) async {
+        _suppressListTileInkAssertion();
+        final estado = await crearEstado();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await tester.pumpAndSettle();
+
+        await tester.tap(find.byKey(const Key('eq-stations-own-eq-row')));
+        await tester.pumpAndSettle();
+
+        expect(find.text('No stations have their own EQ yet.'), findsOneWidget);
+      },
+    );
+
+    testWidgets(
+      'Guardar como preset persists the current bands; the preset appears in the chip row',
+      (tester) async {
+        _suppressListTileInkAssertion();
+        final estado = await crearEstado();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await tester.pumpAndSettle();
+
+        await tester.ensureVisible(
+          find.byKey(const Key('eq-save-preset-action')),
+        );
+        await tester.pumpAndSettle();
+        await tester.tap(find.byKey(const Key('eq-save-preset-action')));
+        await tester.pumpAndSettle();
+
+        await tester.enterText(
+          find.byKey(const Key('eq-save-preset-name-field')),
+          'Mi preset',
+        );
+        await tester.tap(
+          find.byKey(const Key('eq-save-preset-confirm-button')),
+        );
+        await tester.pumpAndSettle();
+
+        expect(find.byType(AlertDialog), findsNothing);
+        expect(find.text('Mi preset'), findsOneWidget);
+        expect(
+          estado.ecualizador.presetsPersonalizados.map((p) => p.nombre),
+          contains('Mi preset'),
+        );
+      },
+    );
+
+    testWidgets(
+      'Guardar como preset with an empty name shows a validation message and persists nothing',
+      (tester) async {
+        _suppressListTileInkAssertion();
+        final estado = await crearEstado();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await tester.pumpAndSettle();
+
+        await tester.ensureVisible(
+          find.byKey(const Key('eq-save-preset-action')),
+        );
+        await tester.pumpAndSettle();
+        await tester.tap(find.byKey(const Key('eq-save-preset-action')));
+        await tester.pumpAndSettle();
+
+        await tester.tap(
+          find.byKey(const Key('eq-save-preset-confirm-button')),
+        );
+        await tester.pumpAndSettle();
+
+        expect(find.byType(AlertDialog), findsOneWidget);
+        expect(find.text('Enter a name for the preset.'), findsOneWidget);
+        expect(estado.ecualizador.presetsPersonalizados, isEmpty);
+      },
+    );
+
+    testWidgets(
+      'Guardar como preset with a whitespace-only name shows the same validation message',
+      (tester) async {
+        _suppressListTileInkAssertion();
+        final estado = await crearEstado();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildScreen(estado));
+        await tester.pumpAndSettle();
+
+        await tester.ensureVisible(
+          find.byKey(const Key('eq-save-preset-action')),
+        );
+        await tester.pumpAndSettle();
+        await tester.tap(find.byKey(const Key('eq-save-preset-action')));
+        await tester.pumpAndSettle();
+
+        await tester.enterText(
+          find.byKey(const Key('eq-save-preset-name-field')),
+          '   ',
+        );
+        await tester.tap(
+          find.byKey(const Key('eq-save-preset-confirm-button')),
+        );
+        await tester.pumpAndSettle();
+
+        expect(find.byType(AlertDialog), findsOneWidget);
+        expect(estado.ecualizador.presetsPersonalizados, isEmpty);
+      },
+    );
+  });
 }

test/servicios/servicio_presets_personalizados_test.dart

@@ -0,0 +1,126 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/modelos/preset_ecualizador.dart';
+import 'package:pluriwave/servicios/servicio_presets_personalizados.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// WU13 task 13.2 — persistence for user-named custom EQ presets.
+///
+/// Design ADR-5 hazard box: this lives in its OWN file and OWN
+/// SharedPreferences key (`eq_custom_presets_v1`), deliberately separate
+/// from `ServicioEcualizador` — that file has an empty-`git diff` success
+/// criterion for this change, so persistence for custom presets must never
+/// be added there.
+void main() {
+  setUp(() {
+    SharedPreferences.setMockInitialValues({});
+  });
+
+  test('listar returns an empty list when nothing was saved yet', () async {
+    final prefs = await SharedPreferences.getInstance();
+    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+
+    expect(await servicio.listar(), isEmpty);
+  });
+
+  test('guardar then listar round-trips a named custom preset', () async {
+    final prefs = await SharedPreferences.getInstance();
+    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+    // Not `const`: PresetEcualizador's constructor asserts `bandas.length
+    // == 5`, and `List.length` is not constant-foldable in an assert here
+    // (same const-eval limitation the branch already hit for
+    // `DateTime(...)` fixtures in WU9) — the model's own static presets
+    // (e.g. `PresetEcualizador.flat`) are declared `final`, not `const`,
+    // for the same reason.
+    final preset = PresetEcualizador(
+      nombre: 'Mi preset',
+      bandas: [1.0, -2.0, 3.0, -4.0, 5.0],
+    );
+
+    await servicio.guardar(preset);
+    final guardados = await servicio.listar();
+
+    expect(guardados, hasLength(1));
+    expect(guardados.single, equals(preset));
+  });
+
+  test('guardar persists under its OWN SharedPreferences key', () async {
+    final prefs = await SharedPreferences.getInstance();
+    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+    final preset = PresetEcualizador(nombre: 'Otro', bandas: [0, 0, 0, 0, 0]);
+
+    await servicio.guardar(preset);
+
+    expect(prefs.getString('eq_custom_presets_v1'), isNotNull);
+  });
+
+  test('guardar with a repeated name replaces the previous entry', () async {
+    final prefs = await SharedPreferences.getInstance();
+    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+    final v1 = PresetEcualizador(nombre: 'Mismo', bandas: [1, 1, 1, 1, 1]);
+    final v2 = PresetEcualizador(nombre: 'Mismo', bandas: [2, 2, 2, 2, 2]);
+
+    await servicio.guardar(v1);
+    await servicio.guardar(v2);
+    final guardados = await servicio.listar();
+
+    expect(guardados, hasLength(1));
+    expect(guardados.single.bandas, equals(v2.bandas));
+  });
+
+  test('guardar preserves insertion order across multiple presets', () async {
+    final prefs = await SharedPreferences.getInstance();
+    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+    final primero = PresetEcualizador(
+      nombre: 'Primero',
+      bandas: [0, 0, 0, 0, 0],
+    );
+    final segundo = PresetEcualizador(
+      nombre: 'Segundo',
+      bandas: [0, 0, 0, 0, 0],
+    );
+
+    await servicio.guardar(primero);
+    await servicio.guardar(segundo);
+    final guardados = await servicio.listar();
+
+    expect(guardados.map((p) => p.nombre).toList(), ['Primero', 'Segundo']);
+  });
+
+  test('eliminar removes the named preset only', () async {
+    final prefs = await SharedPreferences.getInstance();
+    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+    final conservar = PresetEcualizador(
+      nombre: 'Conservar',
+      bandas: [0, 0, 0, 0, 0],
+    );
+    final borrar = PresetEcualizador(nombre: 'Borrar', bandas: [0, 0, 0, 0, 0]);
+    await servicio.guardar(conservar);
+    await servicio.guardar(borrar);
+
+    await servicio.eliminar('Borrar');
+    final guardados = await servicio.listar();
+
+    expect(guardados, hasLength(1));
+    expect(guardados.single.nombre, equals('Conservar'));
+  });
+
+  test('eliminar on an unknown name is a safe no-op', () async {
+    final prefs = await SharedPreferences.getInstance();
+    final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+
+    await servicio.eliminar('no existe');
+
+    expect(await servicio.listar(), isEmpty);
+  });
+
+  test(
+    'a corrupt top-level payload degrades to an empty list, never throws',
+    () async {
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setString('eq_custom_presets_v1', 'not valid json{{{');
+      final servicio = ServicioPresetsPersonalizados(prefs: prefs);
+
+      await expectLater(servicio.listar(), completion(isEmpty));
+    },
+  );
+}

test/widgets/ecualizador_widget_test.dart

@@ -0,0 +1,95 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/l10n/gen/app_localizations.dart';
+import 'package:pluriwave/modelos/preset_ecualizador.dart';
+import 'package:pluriwave/widgets/ecualizador_widget.dart';
+
+/// WU13 task 13.1 — first-class regression guard (design ADR-5, spec
+/// `eq-custom-presets` "Five-Band Equalizer"): the equalizer widget must
+/// always render exactly 5 vertical sliders. Band count is device-reported
+/// via `just_audio`'s `AndroidEqualizer` (spike, Engram id 2498), not
+/// app-chosen — any future change rendering 7 sliders is rejected on sight.
+///
+/// **Correction found at apply time**: `tasks.md`'s WU13 Verify command
+/// names this file as if it already existed ("Modified tests:
+/// ecualizador_widget_test.dart"). No such file existed before this commit
+/// (`ecualizador_widget.dart` had zero test coverage) — created new instead.
+void main() {
+  Widget buildWidget({
+    PresetEcualizador? preset,
+    bool habilitado = true,
+    void Function(PresetEcualizador)? onCambio,
+  }) {
+    return MaterialApp(
+      locale: const Locale('en'),
+      localizationsDelegates: AppLocalizations.localizationsDelegates,
+      supportedLocales: AppLocalizations.supportedLocales,
+      home: Scaffold(
+        body: EcualizadorWidget(
+          preset: preset ?? PresetEcualizador.flat,
+          habilitado: habilitado,
+          onCambio: onCambio ?? (_) {},
+        ),
+      ),
+    );
+  }
+
+  testWidgets('renders exactly 5 vertical sliders, one per band', (
+    tester,
+  ) async {
+    await tester.pumpWidget(buildWidget());
+
+    expect(find.byType(Slider), findsNWidgets(5));
+  });
+
+  testWidgets('renders exactly 5 sliders regardless of the preset selected', (
+    tester,
+  ) async {
+    // Regression guard restated: a future change proposing 7 sliders (the
+    // rejected mockup band count) must fail this test regardless of which
+    // fixed preset is active.
+    await tester.pumpWidget(buildWidget(preset: PresetEcualizador.jazz));
+
+    expect(find.byType(Slider), findsNWidgets(5));
+  });
+
+  testWidgets('dragging a slider reports the updated band back via onCambio', (
+    tester,
+  ) async {
+    PresetEcualizador? reportado;
+    await tester.pumpWidget(buildWidget(onCambio: (p) => reportado = p));
+
+    final slider = tester.widget<Slider>(find.byType(Slider).first);
+    slider.onChanged?.call(6.0);
+    await tester.pump();
+
+    expect(reportado, isNotNull);
+    expect(reportado!.bandas.length, 5);
+    expect(reportado!.bandas.first, 6.0);
+  });
+
+  testWidgets(
+    'habilitado: false disables every slider (greyed, non-interactive)',
+    (tester) async {
+      await tester.pumpWidget(buildWidget(habilitado: false));
+
+      final sliders = tester.widgetList<Slider>(find.byType(Slider));
+      expect(sliders, hasLength(5));
+      for (final slider in sliders) {
+        expect(slider.onChanged, isNull);
+      }
+    },
+  );
+
+  testWidgets('habilitado: true (default) keeps every slider interactive', (
+    tester,
+  ) async {
+    await tester.pumpWidget(buildWidget());
+
+    final sliders = tester.widgetList<Slider>(find.byType(Slider));
+    expect(sliders, hasLength(5));
+    for (final slider in sliders) {
+      expect(slider.onChanged, isNotNull);
+    }
+  });
+}