refactor(ajustes): split remaining Settings sections into pushed screens

lib/l10n/app_en.arb

@@ -55,6 +55,9 @@
   "settingsSubtitle": "Fine-grained sound control, backups, and custom stations.",
   "settingsGroupAudioTitle": "AUDIO",
   "settingsGroupStationsTitle": "STATIONS",
+  "settingsGroupRecordingsTitle": "RECORDINGS & MUSIC",
+  "settingsGroupApplicationTitle": "APPLICATION",
+  "infoSectionTitle": "Info",
   "languageSectionTitle": "Language",
   "languageSectionDescription": "Choose how the app language is displayed.",
   "languageSystemDefault": "System",

lib/l10n/app_es.arb

@@ -55,6 +55,9 @@
   "settingsSubtitle": "Control fino de sonido, copias de seguridad y emisoras personalizadas.",
   "settingsGroupAudioTitle": "AUDIO",
   "settingsGroupStationsTitle": "EMISORAS",
+  "settingsGroupRecordingsTitle": "GRABACIONES Y MÚSICA",
+  "settingsGroupApplicationTitle": "APLICACIÓN",
+  "infoSectionTitle": "Información",
   "languageSectionTitle": "Idioma",
   "languageSectionDescription": "Elegí cómo se muestra el idioma de la app.",
   "languageSystemDefault": "Sistema",

lib/l10n/gen/app_localizations.dart

@@ -286,6 +286,24 @@ abstract class AppLocalizations {
   /// **'EMISORAS'**
   String get settingsGroupStationsTitle;
 
+  /// No description provided for @settingsGroupRecordingsTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'GRABACIONES Y MÚSICA'**
+  String get settingsGroupRecordingsTitle;
+
+  /// No description provided for @settingsGroupApplicationTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'APLICACIÓN'**
+  String get settingsGroupApplicationTitle;
+
+  /// No description provided for @infoSectionTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Información'**
+  String get infoSectionTitle;
+
   /// No description provided for @languageSectionTitle.
   ///
   /// In es, this message translates to:

lib/l10n/gen/app_localizations_ar.dart

@@ -105,6 +105,15 @@ class AppLocalizationsAr extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'اللغة';
 

lib/l10n/gen/app_localizations_bn.dart

@@ -106,6 +106,15 @@ class AppLocalizationsBn extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'ভাষা';
 

lib/l10n/gen/app_localizations_de.dart

@@ -105,6 +105,15 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'Sprache';
 

lib/l10n/gen/app_localizations_en.dart

@@ -105,6 +105,15 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'STATIONS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'RECORDINGS & MUSIC';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APPLICATION';
+
+  @override
+  String get infoSectionTitle => 'Info';
+
   @override
   String get languageSectionTitle => 'Language';
 

lib/l10n/gen/app_localizations_es.dart

@@ -105,6 +105,15 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'Idioma';
 

lib/l10n/gen/app_localizations_fr.dart

@@ -106,6 +106,15 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'Langue';
 

lib/l10n/gen/app_localizations_hi.dart

@@ -105,6 +105,15 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'भाषा';
 

lib/l10n/gen/app_localizations_id.dart

@@ -106,6 +106,15 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'Bahasa';
 

lib/l10n/gen/app_localizations_it.dart

@@ -105,6 +105,15 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'Lingua';
 

lib/l10n/gen/app_localizations_ja.dart

@@ -103,6 +103,15 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => '言語';
 

lib/l10n/gen/app_localizations_pt.dart

@@ -105,6 +105,15 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'Idioma';
 

lib/l10n/gen/app_localizations_ru.dart

@@ -105,6 +105,15 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => 'Язык';
 

lib/l10n/gen/app_localizations_zh.dart

@@ -103,6 +103,15 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get settingsGroupStationsTitle => 'EMISORAS';
 
+  @override
+  String get settingsGroupRecordingsTitle => 'GRABACIONES Y MÚSICA';
+
+  @override
+  String get settingsGroupApplicationTitle => 'APLICACIÓN';
+
+  @override
+  String get infoSectionTitle => 'Información';
+
   @override
   String get languageSectionTitle => '语言';
 

lib/pantallas/ajustes/pantalla_ajustes_backup.dart

@@ -0,0 +1,145 @@
+import 'dart:io';
+
+import 'package:file_picker/file_picker.dart';
+import 'package:flutter/material.dart';
+import 'package:path_provider/path_provider.dart';
+import 'package:provider/provider.dart';
+import 'package:share_plus/share_plus.dart' show Share, XFile;
+
+import '../../estado/estado_radio.dart';
+import '../../l10n/gen/app_localizations.dart';
+import '../../widgets/pluri_glass_surface.dart';
+import '../../widgets/pluri_layout.dart';
+import '../../widgets/pluri_push_scaffold.dart';
+
+/// APLICACIÓN group · "Copia de seguridad" (design ADR-3). Body moved
+/// verbatim from the former `_SeccionBackup` in `pantalla_ajustes.dart` —
+/// only the panel header's icon and title were removed (the pushed screen's
+/// title now carries them); every method below is unchanged.
+class PantallaAjustesBackup extends StatelessWidget {
+  const PantallaAjustesBackup({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    return PluriPushScaffold(
+      title: l10n.backupSectionTitle,
+      body: ListView(
+        padding: PluriLayout.pageContentPadding,
+        children: const [_CuerpoBackup()],
+      ),
+    );
+  }
+}
+
+class _CuerpoBackup extends StatelessWidget {
+  const _CuerpoBackup();
+
+  Future<void> _exportar(BuildContext context) async {
+    final l10n = AppLocalizations.of(context);
+    try {
+      final estado = context.read<EstadoRadio>();
+      // JSON serialization is owned by ServicioExportImport (S4-R4).
+      final json = await estado.exportarConfigJson();
+
+      final dir = await getTemporaryDirectory();
+      final file = File('${dir.path}/pluriwave-backup.json');
+      await file.writeAsString(json);
+
+      await Share.shareXFiles(
+        [XFile(file.path)],
+        subject: l10n.backupShareSubject,
+        text: l10n.backupShareText(DateTime.now().toLocal()),
+      );
+    } catch (e) {
+      if (context.mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(content: Text(l10n.backupExportError(e.toString()))),
+        );
+      }
+    }
+  }
+
+  Future<void> _importar(BuildContext context) async {
+    final l10n = AppLocalizations.of(context);
+    try {
+      final result = await FilePicker.platform.pickFiles(
+        type: FileType.custom,
+        allowedExtensions: ['json'],
+      );
+      if (result == null || result.files.single.path == null) return;
+
+      final file = File(result.files.single.path!);
+      final contenido = await file.readAsString();
+      if (!context.mounted) return;
+      // Parsing is owned by ServicioExportImport (S4-R4): null = malformed.
+      final json = context.read<EstadoRadio>().parsearConfigJson(contenido);
+      if (json == null) {
+        throw const FormatException('invalid backup file');
+      }
+
+      if (context.mounted) {
+        final confirmar = await showDialog<bool>(
+          context: context,
+          builder:
+              (ctx) => AlertDialog(
+                title: Text(AppLocalizations.of(ctx).backupImportTitle),
+                content: Text(
+                  AppLocalizations.of(ctx).backupImportConfirmMessage,
+                ),
+                actions: [
+                  TextButton(
+                    onPressed: () => Navigator.pop(ctx, false),
+                    child: Text(AppLocalizations.of(ctx).cancelAction),
+                  ),
+                  FilledButton(
+                    onPressed: () => Navigator.pop(ctx, true),
+                    child: Text(AppLocalizations.of(ctx).backupImportTitle),
+                  ),
+                ],
+              ),
+        );
+        if (confirmar != true) return;
+        if (context.mounted) {
+          final estado = context.read<EstadoRadio>();
+          final messenger = ScaffoldMessenger.of(context);
+          await estado.importarConfig(json);
+          messenger.showSnackBar(
+            SnackBar(content: Text(l10n.backupImportSuccess)),
+          );
+        }
+      }
+    } catch (e) {
+      if (context.mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(content: Text(l10n.backupImportError(e.toString()))),
+        );
+      }
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return PluriGlassSurface(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          ListTile(
+            contentPadding: EdgeInsets.zero,
+            leading: const Icon(Icons.upload_outlined),
+            title: Text(AppLocalizations.of(context).backupExportTitle),
+            subtitle: Text(AppLocalizations.of(context).backupExportSubtitle),
+            onTap: () => _exportar(context),
+          ),
+          ListTile(
+            contentPadding: EdgeInsets.zero,
+            leading: const Icon(Icons.download_outlined),
+            title: Text(AppLocalizations.of(context).backupImportTitle),
+            subtitle: Text(AppLocalizations.of(context).backupImportSubtitle),
+            onTap: () => _importar(context),
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/pantallas/ajustes/pantalla_ajustes_grabaciones.dart

@@ -0,0 +1,217 @@
+import 'package:file_picker/file_picker.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import '../../estado/estado_grabacion.dart';
+import '../../l10n/gen/app_localizations.dart';
+import '../../widgets/pluri_glass_surface.dart';
+import '../../widgets/pluri_layout.dart';
+import '../../widgets/pluri_push_scaffold.dart';
+
+/// GRABACIONES Y MÚSICA group · "Grabaciones" (design ADR-3). Body moved
+/// verbatim from the former `_SeccionGrabaciones` in `pantalla_ajustes.dart`
+/// — only the panel header's icon and title were removed (the pushed
+/// screen's title now carries them); every method below is unchanged.
+///
+/// Known pre-existing bug, deliberately NOT fixed here (out of scope, moved
+/// verbatim, tracked separately): [_editarTamanoMaximo] disposes its
+/// [TextEditingController] immediately after `showModalBottomSheet` resolves,
+/// racing the sheet's own close animation — the same shape of bug already
+/// documented for `_editarGrupo` in `pantalla_ajustes_grupos_favoritos.dart`.
+class PantallaAjustesGrabaciones extends StatelessWidget {
+  const PantallaAjustesGrabaciones({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    return PluriPushScaffold(
+      title: l10n.recordingsSectionTitle,
+      body: ListView(
+        padding: PluriLayout.pageContentPadding,
+        children: const [_CuerpoGrabaciones()],
+      ),
+    );
+  }
+}
+
+class _CuerpoGrabaciones extends StatelessWidget {
+  const _CuerpoGrabaciones();
+
+  Future<void> _seleccionarRuta(BuildContext context) async {
+    final estado = context.read<EstadoGrabacion>();
+    final messenger = ScaffoldMessenger.of(context);
+    final l10n = AppLocalizations.of(context);
+    final ruta = await FilePicker.platform.getDirectoryPath(
+      dialogTitle: l10n.recordingsFolderDialogTitle,
+    );
+    if (ruta == null) return;
+    try {
+      await estado.cambiarDirectorio(ruta);
+      if (!context.mounted) return;
+      messenger.showSnackBar(
+        SnackBar(content: Text(l10n.recordingsPathUpdated)),
+      );
+    } catch (e) {
+      if (!context.mounted) return;
+      messenger.showSnackBar(
+        SnackBar(content: Text(l10n.recordingsPathSaveError(e.toString()))),
+      );
+    }
+  }
+
+  Future<void> _restaurarRuta(BuildContext context) async {
+    final estado = context.read<EstadoGrabacion>();
+    final messenger = ScaffoldMessenger.of(context);
+    final l10n = AppLocalizations.of(context);
+    await estado.restaurarDirectorio();
+    if (!context.mounted) return;
+    messenger.showSnackBar(
+      SnackBar(content: Text(l10n.recordingsDefaultFolderRestored)),
+    );
+  }
+
+  Future<void> _abrirCarpeta(BuildContext context) async {
+    final estado = context.read<EstadoGrabacion>();
+    final messenger = ScaffoldMessenger.of(context);
+    final l10n = AppLocalizations.of(context);
+    try {
+      final abierto = await estado.abrirDirectorio();
+      if (!context.mounted) return;
+      if (!abierto) {
+        messenger.showSnackBar(
+          SnackBar(content: Text(l10n.recordingsOpenFolderError(l10n.dash))),
+        );
+      }
+    } catch (e) {
+      if (!context.mounted) return;
+      messenger.showSnackBar(
+        SnackBar(content: Text(l10n.recordingsOpenFolderError(e.toString()))),
+      );
+    }
+  }
+
+  Future<void> _editarTamanoMaximo(BuildContext context) async {
+    final estado = context.read<EstadoGrabacion>();
+    final l10n = AppLocalizations.of(context);
+    final actualMb = _bytesAMegabytes(estado.maxBytes);
+    final controller = TextEditingController(text: actualMb.toString());
+
+    final nuevoMb = await showModalBottomSheet<int>(
+      context: context,
+      isScrollControlled: true,
+      showDragHandle: true,
+      builder: (ctx) {
+        final bottom = MediaQuery.viewInsetsOf(ctx).bottom;
+        return Padding(
+          padding: EdgeInsets.fromLTRB(20, 0, 20, bottom + 24),
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Text(
+                l10n.recordingsMaxSizeDialogTitle,
+                style: Theme.of(ctx).textTheme.titleLarge,
+              ),
+              const SizedBox(height: 16),
+              TextField(
+                controller: controller,
+                autofocus: true,
+                keyboardType: TextInputType.number,
+                decoration: InputDecoration(
+                  labelText: l10n.recordingsMaxSizeMbLabel,
+                  border: const OutlineInputBorder(),
+                ),
+              ),
+              const SizedBox(height: 16),
+              FilledButton.icon(
+                onPressed: () {
+                  final value = int.tryParse(controller.text.trim());
+                  if (value == null || value <= 0) return;
+                  Navigator.of(ctx).pop(value);
+                },
+                icon: const Icon(Icons.save_rounded),
+                label: Text(l10n.saveQuickAccessButton),
+              ),
+            ],
+          ),
+        );
+      },
+    );
+    controller.dispose();
+    if (nuevoMb == null || !context.mounted) return;
+    await estado.cambiarMaxBytes(nuevoMb * 1024 * 1024);
+    if (!context.mounted) return;
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(content: Text(l10n.recordingsMaxSizeSaved(nuevoMb))),
+    );
+  }
+
+  int _bytesAMegabytes(int bytes) =>
+      (bytes / (1024 * 1024)).round().clamp(1, 1048576);
+
+  @override
+  Widget build(BuildContext context) {
+    // Recording state lives in EstadoGrabacion (S4-R2): this section only
+    // rebuilds on recording changes, never on playback notifications.
+    final estado = context.watch<EstadoGrabacion>();
+    final l10n = AppLocalizations.of(context);
+
+    return PluriGlassSurface(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          FutureBuilder<String>(
+            future: estado.directorioEfectivo(),
+            builder:
+                (ctx, snap) => ListTile(
+                  contentPadding: EdgeInsets.zero,
+                  leading: const Icon(Icons.folder_outlined),
+                  title: Text(l10n.recordingsFolderTitle),
+                  subtitle: Text(
+                    snap.data ?? l10n.recordingsPathCalculating,
+                    maxLines: 2,
+                    overflow: TextOverflow.ellipsis,
+                  ),
+                ),
+          ),
+          Wrap(
+            spacing: 8,
+            runSpacing: 8,
+            children: [
+              OutlinedButton.icon(
+                icon: const Icon(Icons.folder_open_rounded),
+                label: Text(l10n.recordingsChangePath),
+                onPressed: () => _seleccionarRuta(context),
+              ),
+              FilledButton.tonalIcon(
+                icon: const Icon(Icons.folder_copy_rounded),
+                label: Text(l10n.recordingsOpenFolder),
+                onPressed: () => _abrirCarpeta(context),
+              ),
+              IconButton.filledTonal(
+                tooltip: l10n.recordingsUseDefaultPath,
+                icon: const Icon(Icons.restore_rounded),
+                onPressed: () => _restaurarRuta(context),
+              ),
+            ],
+          ),
+          const SizedBox(height: 8),
+          ListTile(
+            contentPadding: EdgeInsets.zero,
+            leading: const Icon(Icons.sd_storage_rounded),
+            title: Text(l10n.recordingsMaxSizeTitle),
+            subtitle: Text(
+              l10n.recordingsMaxSizeSubtitle(_bytesAMegabytes(estado.maxBytes)),
+            ),
+            onTap: () => _editarTamanoMaximo(context),
+          ),
+          const SizedBox(height: 8),
+          Text(
+            l10n.recordingsOriginalStreamHint,
+            style: Theme.of(context).textTheme.bodySmall,
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/pantallas/ajustes/pantalla_ajustes_idioma.dart

@@ -0,0 +1,131 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import '../../estado/estado_idioma.dart';
+import '../../l10n/gen/app_localizations.dart';
+import '../../widgets/pluri_glass_surface.dart';
+import '../../widgets/pluri_layout.dart';
+import '../../widgets/pluri_push_scaffold.dart';
+
+/// APLICACIÓN group · "Idioma" (design ADR-3). Body moved verbatim from the
+/// former `_SeccionIdioma` (+ `_IdiomaDisponible`) in `pantalla_ajustes.dart`
+/// — only the panel header's icon and title were removed (the pushed
+/// screen's title now carries them); every method and the language list
+/// below is unchanged.
+class PantallaAjustesIdioma extends StatelessWidget {
+  const PantallaAjustesIdioma({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    return PluriPushScaffold(
+      title: l10n.languageSectionTitle,
+      body: ListView(
+        padding: PluriLayout.pageContentPadding,
+        children: const [_CuerpoIdioma()],
+      ),
+    );
+  }
+}
+
+class _CuerpoIdioma extends StatelessWidget {
+  const _CuerpoIdioma();
+
+  static const _codigoSistema = 'system';
+  static const _idiomas = [
+    _IdiomaDisponible(Locale('en'), 'English'),
+    _IdiomaDisponible(Locale('es'), 'Español'),
+    _IdiomaDisponible(Locale('zh'), '中文'),
+    _IdiomaDisponible(Locale('hi'), 'हिन्दी'),
+    _IdiomaDisponible(Locale('ar'), 'العربية'),
+    _IdiomaDisponible(Locale('pt'), 'Português'),
+    _IdiomaDisponible(Locale('fr'), 'Français'),
+    _IdiomaDisponible(Locale('ru'), 'Русский'),
+    _IdiomaDisponible(Locale('de'), 'Deutsch'),
+    _IdiomaDisponible(Locale('ja'), '日本語'),
+    _IdiomaDisponible(Locale('id'), 'Bahasa Indonesia'),
+    _IdiomaDisponible(Locale('bn'), 'বাংলা'),
+    _IdiomaDisponible(Locale('it'), 'Italiano'),
+  ];
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    final estadoIdioma = context.watch<EstadoIdioma>();
+    final locale = estadoIdioma.localeSeleccionado;
+    final valorActual = locale == null ? _codigoSistema : _codigoLocale(locale);
+
+    return PluriGlassSurface(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          const SizedBox(height: 8),
+          Text(
+            l10n.languageSectionDescription,
+            style: Theme.of(context).textTheme.bodySmall,
+          ),
+          const SizedBox(height: 12),
+          DropdownButtonFormField<String>(
+            initialValue: valorActual,
+            decoration: InputDecoration(
+              labelText: l10n.languageSectionTitle,
+              border: const OutlineInputBorder(),
+            ),
+            items: [
+              DropdownMenuItem(
+                value: _codigoSistema,
+                child: Text(l10n.languageSystemDefault),
+              ),
+              for (final idioma in _idiomas)
+                DropdownMenuItem(
+                  value: _codigoLocale(idioma.locale),
+                  child: Text(idioma.nombreNativo),
+                ),
+            ],
+            onChanged: (codigo) async {
+              if (codigo == null) return;
+              if (codigo == _codigoSistema) {
+                await context.read<EstadoIdioma>().seleccionarSistema();
+                if (!context.mounted) return;
+                ScaffoldMessenger.of(context).showSnackBar(
+                  SnackBar(content: Text(l10n.languageUpdatedSystem)),
+                );
+                return;
+              }
+
+              final idioma = _idiomas.firstWhere(
+                (item) => _codigoLocale(item.locale) == codigo,
+                orElse: () => _idiomas.first,
+              );
+              await context.read<EstadoIdioma>().seleccionarLocale(
+                idioma.locale,
+              );
+              if (!context.mounted) return;
+
+              ScaffoldMessenger.of(context).showSnackBar(
+                SnackBar(
+                  content: Text(l10n.languageUpdated(idioma.nombreNativo)),
+                ),
+              );
+            },
+          ),
+        ],
+      ),
+    );
+  }
+
+  static String _codigoLocale(Locale locale) {
+    final countryCode = locale.countryCode;
+    if (countryCode == null || countryCode.isEmpty) {
+      return locale.languageCode;
+    }
+    return '${locale.languageCode}_$countryCode';
+  }
+}
+
+class _IdiomaDisponible {
+  const _IdiomaDisponible(this.locale, this.nombreNativo);
+
+  final Locale locale;
+  final String nombreNativo;
+}

lib/pantallas/ajustes/pantalla_ajustes_info.dart

@@ -0,0 +1,120 @@
+import 'package:flutter/material.dart';
+import 'package:package_info_plus/package_info_plus.dart';
+import 'package:provider/provider.dart';
+
+import '../../estado/estado_radio.dart';
+import '../../l10n/gen/app_localizations.dart';
+import '../../widgets/pluri_glass_surface.dart';
+import '../../widgets/pluri_icon.dart';
+import '../../widgets/pluri_layout.dart';
+import '../../widgets/pluri_onboarding_dialog.dart';
+import '../../widgets/pluri_push_scaffold.dart';
+
+/// APLICACIÓN group · "Info" (design ADR-3). Body moved verbatim from the
+/// former `_SeccionInfo` in `pantalla_ajustes.dart`. Unlike the other four
+/// sections in this batch, `_SeccionInfo` never had its own header
+/// icon+title row — its first tile (app name + version) already served that
+/// role — so there is no header row to strip here; the body below is
+/// unchanged in full. `infoSectionTitle` is the one new ARB key this screen
+/// needed, since no existing in-body header string covers a bare "Info"
+/// label (see WU3b's apply-progress note).
+class PantallaAjustesInfo extends StatelessWidget {
+  const PantallaAjustesInfo({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    return PluriPushScaffold(
+      title: l10n.infoSectionTitle,
+      body: ListView(
+        padding: PluriLayout.pageContentPadding,
+        children: const [_CuerpoInfo()],
+      ),
+    );
+  }
+}
+
+class _CuerpoInfo extends StatelessWidget {
+  const _CuerpoInfo();
+
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<EstadoRadio>(
+      builder:
+          (ctx, estado, _) => PluriGlassSurface(
+            child: Column(
+              children: [
+                FutureBuilder<PackageInfo>(
+                  future: PackageInfo.fromPlatform(),
+                  builder: (ctx, snap) {
+                    final version =
+                        snap.hasData
+                            ? 'v${snap.data!.version}+${snap.data!.buildNumber}'
+                            : AppLocalizations.of(ctx).appVersionLoading;
+                    return ListTile(
+                      contentPadding: EdgeInsets.zero,
+                      leading: const PluriIcon(
+                        glyph: PluriIconGlyph.settings,
+                        variant: PluriIconVariant.filled,
+                      ),
+                      title: Text(AppLocalizations.of(ctx).appTitle),
+                      subtitle: Text(
+                        AppLocalizations.of(ctx).appVersionSubtitle(version),
+                      ),
+                    );
+                  },
+                ),
+                FutureBuilder<int>(
+                  future: estado.favoritos.obtenerTodos().then((l) => l.length),
+                  builder:
+                      (ctx, snap) => ListTile(
+                        contentPadding: EdgeInsets.zero,
+                        leading: const Icon(Icons.favorite_outline_rounded),
+                        title: Text(
+                          AppLocalizations.of(ctx).savedFavoritesTitle,
+                        ),
+                        trailing: Text(
+                          snap.data?.toString() ??
+                              AppLocalizations.of(ctx).dash,
+                          style: Theme.of(ctx).textTheme.bodyLarge,
+                        ),
+                      ),
+                ),
+                ListTile(
+                  contentPadding: EdgeInsets.zero,
+                  leading: const Icon(Icons.help_outline_rounded),
+                  title: Text(AppLocalizations.of(ctx).helpTitle),
+                  subtitle: Text(AppLocalizations.of(ctx).helpSubtitle),
+                  trailing: const Icon(Icons.chevron_right_rounded),
+                  onTap: () => PluriOnboardingDialog.mostrar(ctx),
+                ),
+                ListTile(
+                  contentPadding: EdgeInsets.zero,
+                  leading: const Icon(Icons.verified_outlined),
+                  title: Text(AppLocalizations.of(ctx).stationFilterTitle),
+                  subtitle: Text(
+                    AppLocalizations.of(ctx).stationFilterSubtitle,
+                  ),
+                  trailing: Icon(
+                    Icons.check_circle_rounded,
+                    color: Theme.of(ctx).colorScheme.secondary,
+                  ),
+                ),
+                ListTile(
+                  contentPadding: EdgeInsets.zero,
+                  leading: const Icon(Icons.music_note_outlined),
+                  title: Text(AppLocalizations.of(ctx).backgroundAudioTitle),
+                  subtitle: Text(
+                    AppLocalizations.of(ctx).backgroundAudioSubtitle,
+                  ),
+                  trailing: Icon(
+                    Icons.check_circle_rounded,
+                    color: Theme.of(ctx).colorScheme.secondary,
+                  ),
+                ),
+              ],
+            ),
+          ),
+    );
+  }
+}

lib/pantallas/ajustes/pantalla_ajustes_musica_local.dart

@@ -0,0 +1,129 @@
+import 'package:flutter/material.dart';
+
+import '../../l10n/gen/app_localizations.dart';
+import '../../servicios/musica_local_auto.dart';
+import '../../widgets/pluri_glass_surface.dart';
+import '../../widgets/pluri_layout.dart';
+import '../../widgets/pluri_push_scaffold.dart';
+
+/// GRABACIONES Y MÚSICA group · "Música local" (design ADR-3). Body moved
+/// verbatim from the former `_SeccionMusicaLocal` in `pantalla_ajustes.dart`
+/// — only the panel header's icon and title were removed (the pushed
+/// screen's title now carries them). Deliberately does NOT use
+/// `FilePicker.platform` (see tasks.md "Grounding corrections") —
+/// [FuenteMusicaLocalAutoImpl.elegirCarpeta] calls the native
+/// `pickMusicFolder` channel method directly, since it needs a
+/// persistable-grant SAF tree URI, not a plain filesystem path.
+class PantallaAjustesMusicaLocal extends StatelessWidget {
+  const PantallaAjustesMusicaLocal({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    return PluriPushScaffold(
+      title: l10n.localMusicSectionTitle,
+      body: ListView(
+        padding: PluriLayout.pageContentPadding,
+        children: const [_CuerpoMusicaLocal()],
+      ),
+    );
+  }
+}
+
+class _CuerpoMusicaLocal extends StatefulWidget {
+  const _CuerpoMusicaLocal();
+
+  @override
+  State<_CuerpoMusicaLocal> createState() => _CuerpoMusicaLocalState();
+}
+
+class _CuerpoMusicaLocalState extends State<_CuerpoMusicaLocal> {
+  final _fuente = FuenteMusicaLocalAutoImpl();
+  late Future<String?> _carpetaActual;
+
+  @override
+  void initState() {
+    super.initState();
+    _carpetaActual = _fuente.carpetaActual();
+  }
+
+  Future<void> _elegirCarpeta(BuildContext context) async {
+    final messenger = ScaffoldMessenger.of(context);
+    final l10n = AppLocalizations.of(context);
+    try {
+      final uri = await _fuente.elegirCarpeta();
+      if (uri == null) return; // Cancelled — no snackbar, matches the SAF
+      // picker's own "nothing changed" affordance.
+      if (!context.mounted) return;
+      setState(() {
+        _carpetaActual = Future.value(uri);
+      });
+      messenger.showSnackBar(
+        SnackBar(content: Text(l10n.localMusicFolderUpdated)),
+      );
+    } catch (e) {
+      if (!context.mounted) return;
+      messenger.showSnackBar(
+        SnackBar(content: Text(l10n.localMusicFolderSaveError(e.toString()))),
+      );
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+
+    return PluriGlassSurface(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          const SizedBox(height: 8),
+          Text(
+            l10n.localMusicSectionDescription,
+            style: Theme.of(context).textTheme.bodySmall,
+          ),
+          FutureBuilder<String?>(
+            future: _carpetaActual,
+            builder: (ctx, snap) {
+              final carpeta = snap.data;
+              return ListTile(
+                contentPadding: EdgeInsets.zero,
+                leading: const Icon(Icons.folder_outlined),
+                title: Text(l10n.localMusicFolderTitle),
+                subtitle: Text(
+                  (carpeta == null || carpeta.isEmpty)
+                      ? l10n.localMusicFolderNotConfigured
+                      : nombreCarpetaDesdeUri(
+                        carpeta,
+                        nombreGenerico: l10n.localMusicFolderGenericName,
+                      ),
+                  maxLines: 2,
+                  overflow: TextOverflow.ellipsis,
+                ),
+              );
+            },
+          ),
+          const SizedBox(height: 8),
+          FutureBuilder<String?>(
+            future: _carpetaActual,
+            builder: (ctx, snap) {
+              final configurada = (snap.data ?? '').isNotEmpty;
+              return Align(
+                alignment: Alignment.centerLeft,
+                child: OutlinedButton.icon(
+                  icon: const Icon(Icons.folder_open_rounded),
+                  label: Text(
+                    configurada
+                        ? l10n.localMusicChangePath
+                        : l10n.localMusicChoosePath,
+                  ),
+                  onPressed: () => _elegirCarpeta(context),
+                ),
+              );
+            },
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/pantallas/pantalla_ajustes.dart

@@ -1,28 +1,19 @@
-import 'dart:async';
-import 'dart:io';
-
-import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
-import 'package:package_info_plus/package_info_plus.dart';
-import 'package:path_provider/path_provider.dart';
-import 'package:provider/provider.dart';
-import 'package:share_plus/share_plus.dart' show Share, XFile;
 
-import '../estado/estado_grabacion.dart';
-import '../estado/estado_idioma.dart';
-import '../estado/estado_radio.dart';
 import '../l10n/gen/app_localizations.dart';
-import '../servicios/musica_local_auto.dart';
-import '../widgets/pluri_glass_surface.dart';
 import '../widgets/pluri_icon.dart';
 import '../widgets/pluri_layout.dart';
-import '../widgets/pluri_onboarding_dialog.dart';
 import '../widgets/pluri_premium_widgets.dart';
 import '../widgets/pluri_push_scaffold.dart';
+import 'ajustes/pantalla_ajustes_backup.dart';
 import 'ajustes/pantalla_ajustes_ecualizador.dart';
 import 'ajustes/pantalla_ajustes_emisora_preferida.dart';
 import 'ajustes/pantalla_ajustes_emisoras_personalizadas.dart';
+import 'ajustes/pantalla_ajustes_grabaciones.dart';
 import 'ajustes/pantalla_ajustes_grupos_favoritos.dart';
+import 'ajustes/pantalla_ajustes_idioma.dart';
+import 'ajustes/pantalla_ajustes_info.dart';
+import 'ajustes/pantalla_ajustes_musica_local.dart';
 import 'ajustes/pantalla_ajustes_orden_listas.dart';
 import 'ajustes/pantalla_ajustes_salida_audio.dart';
 import 'ajustes/pantalla_ajustes_timer_sueno.dart';
@@ -56,13 +47,11 @@ class PantallaAjustes extends StatelessWidget {
   }
 }
 
-/// Design ADR-3: the AUDIO and EMISORAS groups are grouped nav rows only —
-/// each [FilaAjuste] pushes its own detail screen via
-/// `PluriPushScaffold.push`, carrying zero inline controls in the root.
-///
-/// The remaining sections (GRABACIONES Y MÚSICA, APLICACIÓN) still render
-/// inline here pending WU3b, which decomposes them the same way. Sleep timer
-/// and backup/restore stay reachable throughout — nothing is dropped.
+/// Design ADR-3: the Settings root is grouped nav rows only — each
+/// [FilaAjuste] pushes its own detail screen via `PluriPushScaffold.push`,
+/// carrying zero inline controls. All 12 sections are now decomposed across
+/// WU3a (AUDIO, EMISORAS) and WU3b (GRABACIONES Y MÚSICA, APLICACIÓN); sleep
+/// timer and backup/restore stay reachable throughout — nothing was dropped.
 class _AjustesContent extends StatelessWidget {
   const _AjustesContent();
 
@@ -147,642 +136,63 @@ class _AjustesContent extends StatelessWidget {
           ],
         ),
         const SizedBox(height: 12),
-        const _SeccionGrabaciones(),
+        GrupoAjustes(
+          titulo: l10n.settingsGroupRecordingsTitle,
+          filas: [
+            FilaAjuste(
+              icon: Icons.radio_button_checked_rounded,
+              titulo: l10n.recordingsSectionTitle,
+              onTap:
+                  () => PluriPushScaffold.push(
+                    context,
+                    (_) => const PantallaAjustesGrabaciones(),
+                  ),
+            ),
+            FilaAjuste(
+              icon: Icons.library_music_outlined,
+              titulo: l10n.localMusicSectionTitle,
+              onTap:
+                  () => PluriPushScaffold.push(
+                    context,
+                    (_) => const PantallaAjustesMusicaLocal(),
+                  ),
+            ),
+          ],
+        ),
         const SizedBox(height: 12),
-        const _SeccionMusicaLocal(),
-        const SizedBox(height: 12),
-        const _SeccionIdioma(),
-        const SizedBox(height: 12),
-        const _SeccionBackup(),
-        const SizedBox(height: 12),
-        const _SeccionInfo(),
+        GrupoAjustes(
+          titulo: l10n.settingsGroupApplicationTitle,
+          filas: [
+            FilaAjuste(
+              icon: Icons.language_rounded,
+              titulo: l10n.languageSectionTitle,
+              onTap:
+                  () => PluriPushScaffold.push(
+                    context,
+                    (_) => const PantallaAjustesIdioma(),
+                  ),
+            ),
+            FilaAjuste(
+              icon: Icons.backup_outlined,
+              titulo: l10n.backupSectionTitle,
+              onTap:
+                  () => PluriPushScaffold.push(
+                    context,
+                    (_) => const PantallaAjustesBackup(),
+                  ),
+            ),
+            FilaAjuste(
+              icon: Icons.info_outline_rounded,
+              titulo: l10n.infoSectionTitle,
+              onTap:
+                  () => PluriPushScaffold.push(
+                    context,
+                    (_) => const PantallaAjustesInfo(),
+                  ),
+            ),
+          ],
+        ),
       ],
     );
   }
 }
-
-class _SeccionGrabaciones extends StatelessWidget {
-  const _SeccionGrabaciones();
-
-  Future<void> _seleccionarRuta(BuildContext context) async {
-    final estado = context.read<EstadoGrabacion>();
-    final messenger = ScaffoldMessenger.of(context);
-    final l10n = AppLocalizations.of(context);
-    final ruta = await FilePicker.platform.getDirectoryPath(
-      dialogTitle: l10n.recordingsFolderDialogTitle,
-    );
-    if (ruta == null) return;
-    try {
-      await estado.cambiarDirectorio(ruta);
-      if (!context.mounted) return;
-      messenger.showSnackBar(
-        SnackBar(content: Text(l10n.recordingsPathUpdated)),
-      );
-    } catch (e) {
-      if (!context.mounted) return;
-      messenger.showSnackBar(
-        SnackBar(content: Text(l10n.recordingsPathSaveError(e.toString()))),
-      );
-    }
-  }
-
-  Future<void> _restaurarRuta(BuildContext context) async {
-    final estado = context.read<EstadoGrabacion>();
-    final messenger = ScaffoldMessenger.of(context);
-    final l10n = AppLocalizations.of(context);
-    await estado.restaurarDirectorio();
-    if (!context.mounted) return;
-    messenger.showSnackBar(
-      SnackBar(content: Text(l10n.recordingsDefaultFolderRestored)),
-    );
-  }
-
-  Future<void> _abrirCarpeta(BuildContext context) async {
-    final estado = context.read<EstadoGrabacion>();
-    final messenger = ScaffoldMessenger.of(context);
-    final l10n = AppLocalizations.of(context);
-    try {
-      final abierto = await estado.abrirDirectorio();
-      if (!context.mounted) return;
-      if (!abierto) {
-        messenger.showSnackBar(
-          SnackBar(content: Text(l10n.recordingsOpenFolderError(l10n.dash))),
-        );
-      }
-    } catch (e) {
-      if (!context.mounted) return;
-      messenger.showSnackBar(
-        SnackBar(content: Text(l10n.recordingsOpenFolderError(e.toString()))),
-      );
-    }
-  }
-
-  Future<void> _editarTamanoMaximo(BuildContext context) async {
-    final estado = context.read<EstadoGrabacion>();
-    final l10n = AppLocalizations.of(context);
-    final actualMb = _bytesAMegabytes(estado.maxBytes);
-    final controller = TextEditingController(text: actualMb.toString());
-
-    final nuevoMb = await showModalBottomSheet<int>(
-      context: context,
-      isScrollControlled: true,
-      showDragHandle: true,
-      builder: (ctx) {
-        final bottom = MediaQuery.viewInsetsOf(ctx).bottom;
-        return Padding(
-          padding: EdgeInsets.fromLTRB(20, 0, 20, bottom + 24),
-          child: Column(
-            mainAxisSize: MainAxisSize.min,
-            crossAxisAlignment: CrossAxisAlignment.start,
-            children: [
-              Text(
-                l10n.recordingsMaxSizeDialogTitle,
-                style: Theme.of(ctx).textTheme.titleLarge,
-              ),
-              const SizedBox(height: 16),
-              TextField(
-                controller: controller,
-                autofocus: true,
-                keyboardType: TextInputType.number,
-                decoration: InputDecoration(
-                  labelText: l10n.recordingsMaxSizeMbLabel,
-                  border: const OutlineInputBorder(),
-                ),
-              ),
-              const SizedBox(height: 16),
-              FilledButton.icon(
-                onPressed: () {
-                  final value = int.tryParse(controller.text.trim());
-                  if (value == null || value <= 0) return;
-                  Navigator.of(ctx).pop(value);
-                },
-                icon: const Icon(Icons.save_rounded),
-                label: Text(l10n.saveQuickAccessButton),
-              ),
-            ],
-          ),
-        );
-      },
-    );
-    controller.dispose();
-    if (nuevoMb == null || !context.mounted) return;
-    await estado.cambiarMaxBytes(nuevoMb * 1024 * 1024);
-    if (!context.mounted) return;
-    ScaffoldMessenger.of(context).showSnackBar(
-      SnackBar(content: Text(l10n.recordingsMaxSizeSaved(nuevoMb))),
-    );
-  }
-
-  int _bytesAMegabytes(int bytes) =>
-      (bytes / (1024 * 1024)).round().clamp(1, 1048576);
-
-  @override
-  Widget build(BuildContext context) {
-    // Recording state lives in EstadoGrabacion (S4-R2): this section only
-    // rebuilds on recording changes, never on playback notifications.
-    final estado = context.watch<EstadoGrabacion>();
-    final l10n = AppLocalizations.of(context);
-
-    return PluriGlassSurface(
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          Row(
-            children: [
-              const Icon(Icons.radio_button_checked_rounded),
-              const SizedBox(width: 12),
-              Text(
-                l10n.recordingsSectionTitle,
-                style: Theme.of(context).textTheme.titleMedium,
-              ),
-            ],
-          ),
-          FutureBuilder<String>(
-            future: estado.directorioEfectivo(),
-            builder:
-                (ctx, snap) => ListTile(
-                  contentPadding: EdgeInsets.zero,
-                  leading: const Icon(Icons.folder_outlined),
-                  title: Text(l10n.recordingsFolderTitle),
-                  subtitle: Text(
-                    snap.data ?? l10n.recordingsPathCalculating,
-                    maxLines: 2,
-                    overflow: TextOverflow.ellipsis,
-                  ),
-                ),
-          ),
-          Wrap(
-            spacing: 8,
-            runSpacing: 8,
-            children: [
-              OutlinedButton.icon(
-                icon: const Icon(Icons.folder_open_rounded),
-                label: Text(l10n.recordingsChangePath),
-                onPressed: () => _seleccionarRuta(context),
-              ),
-              FilledButton.tonalIcon(
-                icon: const Icon(Icons.folder_copy_rounded),
-                label: Text(l10n.recordingsOpenFolder),
-                onPressed: () => _abrirCarpeta(context),
-              ),
-              IconButton.filledTonal(
-                tooltip: l10n.recordingsUseDefaultPath,
-                icon: const Icon(Icons.restore_rounded),
-                onPressed: () => _restaurarRuta(context),
-              ),
-            ],
-          ),
-          const SizedBox(height: 8),
-          ListTile(
-            contentPadding: EdgeInsets.zero,
-            leading: const Icon(Icons.sd_storage_rounded),
-            title: Text(l10n.recordingsMaxSizeTitle),
-            subtitle: Text(
-              l10n.recordingsMaxSizeSubtitle(_bytesAMegabytes(estado.maxBytes)),
-            ),
-            onTap: () => _editarTamanoMaximo(context),
-          ),
-          const SizedBox(height: 8),
-          Text(
-            l10n.recordingsOriginalStreamHint,
-            style: Theme.of(context).textTheme.bodySmall,
-          ),
-        ],
-      ),
-    );
-  }
-}
-
-/// Local-music root-folder picker (android-auto-local-music task 9),
-/// mirroring [_SeccionGrabaciones]'s shape: `PluriGlassSurface` card,
-/// `FutureBuilder`-driven current-folder display, a single action button and
-/// snackbar feedback. Deliberately does NOT use `FilePicker.platform` (see
-/// tasks.md "Grounding corrections") — [FuenteMusicaLocalAutoImpl.elegirCarpeta]
-/// calls the NEW native `pickMusicFolder` channel method directly, since it
-/// needs a persistable-grant SAF tree URI, not a plain filesystem path.
-class _SeccionMusicaLocal extends StatefulWidget {
-  const _SeccionMusicaLocal();
-
-  @override
-  State<_SeccionMusicaLocal> createState() => _SeccionMusicaLocalState();
-}
-
-class _SeccionMusicaLocalState extends State<_SeccionMusicaLocal> {
-  final _fuente = FuenteMusicaLocalAutoImpl();
-  late Future<String?> _carpetaActual;
-
-  @override
-  void initState() {
-    super.initState();
-    _carpetaActual = _fuente.carpetaActual();
-  }
-
-  Future<void> _elegirCarpeta(BuildContext context) async {
-    final messenger = ScaffoldMessenger.of(context);
-    final l10n = AppLocalizations.of(context);
-    try {
-      final uri = await _fuente.elegirCarpeta();
-      if (uri == null) return; // Cancelled — no snackbar, matches the SAF
-      // picker's own "nothing changed" affordance.
-      if (!context.mounted) return;
-      setState(() {
-        _carpetaActual = Future.value(uri);
-      });
-      messenger.showSnackBar(
-        SnackBar(content: Text(l10n.localMusicFolderUpdated)),
-      );
-    } catch (e) {
-      if (!context.mounted) return;
-      messenger.showSnackBar(
-        SnackBar(content: Text(l10n.localMusicFolderSaveError(e.toString()))),
-      );
-    }
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    final l10n = AppLocalizations.of(context);
-
-    return PluriGlassSurface(
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          Row(
-            children: [
-              const Icon(Icons.library_music_outlined),
-              const SizedBox(width: 12),
-              Text(
-                l10n.localMusicSectionTitle,
-                style: Theme.of(context).textTheme.titleMedium,
-              ),
-            ],
-          ),
-          const SizedBox(height: 8),
-          Text(
-            l10n.localMusicSectionDescription,
-            style: Theme.of(context).textTheme.bodySmall,
-          ),
-          FutureBuilder<String?>(
-            future: _carpetaActual,
-            builder: (ctx, snap) {
-              final carpeta = snap.data;
-              return ListTile(
-                contentPadding: EdgeInsets.zero,
-                leading: const Icon(Icons.folder_outlined),
-                title: Text(l10n.localMusicFolderTitle),
-                subtitle: Text(
-                  (carpeta == null || carpeta.isEmpty)
-                      ? l10n.localMusicFolderNotConfigured
-                      : nombreCarpetaDesdeUri(
-                        carpeta,
-                        nombreGenerico: l10n.localMusicFolderGenericName,
-                      ),
-                  maxLines: 2,
-                  overflow: TextOverflow.ellipsis,
-                ),
-              );
-            },
-          ),
-          const SizedBox(height: 8),
-          FutureBuilder<String?>(
-            future: _carpetaActual,
-            builder: (ctx, snap) {
-              final configurada = (snap.data ?? '').isNotEmpty;
-              return Align(
-                alignment: Alignment.centerLeft,
-                child: OutlinedButton.icon(
-                  icon: const Icon(Icons.folder_open_rounded),
-                  label: Text(
-                    configurada
-                        ? l10n.localMusicChangePath
-                        : l10n.localMusicChoosePath,
-                  ),
-                  onPressed: () => _elegirCarpeta(context),
-                ),
-              );
-            },
-          ),
-        ],
-      ),
-    );
-  }
-}
-
-class _SeccionIdioma extends StatelessWidget {
-  const _SeccionIdioma();
-
-  static const _codigoSistema = 'system';
-  static const _idiomas = [
-    _IdiomaDisponible(Locale('en'), 'English'),
-    _IdiomaDisponible(Locale('es'), 'Español'),
-    _IdiomaDisponible(Locale('zh'), '中文'),
-    _IdiomaDisponible(Locale('hi'), 'हिन्दी'),
-    _IdiomaDisponible(Locale('ar'), 'العربية'),
-    _IdiomaDisponible(Locale('pt'), 'Português'),
-    _IdiomaDisponible(Locale('fr'), 'Français'),
-    _IdiomaDisponible(Locale('ru'), 'Русский'),
-    _IdiomaDisponible(Locale('de'), 'Deutsch'),
-    _IdiomaDisponible(Locale('ja'), '日本語'),
-    _IdiomaDisponible(Locale('id'), 'Bahasa Indonesia'),
-    _IdiomaDisponible(Locale('bn'), 'বাংলা'),
-    _IdiomaDisponible(Locale('it'), 'Italiano'),
-  ];
-
-  @override
-  Widget build(BuildContext context) {
-    final l10n = AppLocalizations.of(context);
-    final estadoIdioma = context.watch<EstadoIdioma>();
-    final locale = estadoIdioma.localeSeleccionado;
-    final valorActual = locale == null ? _codigoSistema : _codigoLocale(locale);
-
-    return PluriGlassSurface(
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          Row(
-            children: [
-              const Icon(Icons.language_rounded),
-              const SizedBox(width: 12),
-              Text(
-                l10n.languageSectionTitle,
-                style: Theme.of(context).textTheme.titleMedium,
-              ),
-            ],
-          ),
-          const SizedBox(height: 8),
-          Text(
-            l10n.languageSectionDescription,
-            style: Theme.of(context).textTheme.bodySmall,
-          ),
-          const SizedBox(height: 12),
-          DropdownButtonFormField<String>(
-            initialValue: valorActual,
-            decoration: InputDecoration(
-              labelText: l10n.languageSectionTitle,
-              border: const OutlineInputBorder(),
-            ),
-            items: [
-              DropdownMenuItem(
-                value: _codigoSistema,
-                child: Text(l10n.languageSystemDefault),
-              ),
-              for (final idioma in _idiomas)
-                DropdownMenuItem(
-                  value: _codigoLocale(idioma.locale),
-                  child: Text(idioma.nombreNativo),
-                ),
-            ],
-            onChanged: (codigo) async {
-              if (codigo == null) return;
-              if (codigo == _codigoSistema) {
-                await context.read<EstadoIdioma>().seleccionarSistema();
-                if (!context.mounted) return;
-                ScaffoldMessenger.of(context).showSnackBar(
-                  SnackBar(content: Text(l10n.languageUpdatedSystem)),
-                );
-                return;
-              }
-
-              final idioma = _idiomas.firstWhere(
-                (item) => _codigoLocale(item.locale) == codigo,
-                orElse: () => _idiomas.first,
-              );
-              await context.read<EstadoIdioma>().seleccionarLocale(
-                idioma.locale,
-              );
-              if (!context.mounted) return;
-
-              ScaffoldMessenger.of(context).showSnackBar(
-                SnackBar(
-                  content: Text(l10n.languageUpdated(idioma.nombreNativo)),
-                ),
-              );
-            },
-          ),
-        ],
-      ),
-    );
-  }
-
-  static String _codigoLocale(Locale locale) {
-    final countryCode = locale.countryCode;
-    if (countryCode == null || countryCode.isEmpty) {
-      return locale.languageCode;
-    }
-    return '${locale.languageCode}_$countryCode';
-  }
-}
-
-class _IdiomaDisponible {
-  const _IdiomaDisponible(this.locale, this.nombreNativo);
-
-  final Locale locale;
-  final String nombreNativo;
-}
-
-class _SeccionBackup extends StatelessWidget {
-  const _SeccionBackup();
-
-  Future<void> _exportar(BuildContext context) async {
-    final l10n = AppLocalizations.of(context);
-    try {
-      final estado = context.read<EstadoRadio>();
-      // JSON serialization is owned by ServicioExportImport (S4-R4).
-      final json = await estado.exportarConfigJson();
-
-      final dir = await getTemporaryDirectory();
-      final file = File('${dir.path}/pluriwave-backup.json');
-      await file.writeAsString(json);
-
-      await Share.shareXFiles(
-        [XFile(file.path)],
-        subject: l10n.backupShareSubject,
-        text: l10n.backupShareText(DateTime.now().toLocal()),
-      );
-    } catch (e) {
-      if (context.mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          SnackBar(content: Text(l10n.backupExportError(e.toString()))),
-        );
-      }
-    }
-  }
-
-  Future<void> _importar(BuildContext context) async {
-    final l10n = AppLocalizations.of(context);
-    try {
-      final result = await FilePicker.platform.pickFiles(
-        type: FileType.custom,
-        allowedExtensions: ['json'],
-      );
-      if (result == null || result.files.single.path == null) return;
-
-      final file = File(result.files.single.path!);
-      final contenido = await file.readAsString();
-      if (!context.mounted) return;
-      // Parsing is owned by ServicioExportImport (S4-R4): null = malformed.
-      final json = context.read<EstadoRadio>().parsearConfigJson(contenido);
-      if (json == null) {
-        throw const FormatException('invalid backup file');
-      }
-
-      if (context.mounted) {
-        final confirmar = await showDialog<bool>(
-          context: context,
-          builder:
-              (ctx) => AlertDialog(
-                title: Text(AppLocalizations.of(ctx).backupImportTitle),
-                content: Text(
-                  AppLocalizations.of(ctx).backupImportConfirmMessage,
-                ),
-                actions: [
-                  TextButton(
-                    onPressed: () => Navigator.pop(ctx, false),
-                    child: Text(AppLocalizations.of(ctx).cancelAction),
-                  ),
-                  FilledButton(
-                    onPressed: () => Navigator.pop(ctx, true),
-                    child: Text(AppLocalizations.of(ctx).backupImportTitle),
-                  ),
-                ],
-              ),
-        );
-        if (confirmar != true) return;
-        if (context.mounted) {
-          final estado = context.read<EstadoRadio>();
-          final messenger = ScaffoldMessenger.of(context);
-          await estado.importarConfig(json);
-          messenger.showSnackBar(
-            SnackBar(content: Text(l10n.backupImportSuccess)),
-          );
-        }
-      }
-    } catch (e) {
-      if (context.mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          SnackBar(content: Text(l10n.backupImportError(e.toString()))),
-        );
-      }
-    }
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return PluriGlassSurface(
-      child: Column(
-        crossAxisAlignment: CrossAxisAlignment.start,
-        children: [
-          Row(
-            children: [
-              const Icon(Icons.backup_outlined),
-              const SizedBox(width: 12),
-              Text(
-                AppLocalizations.of(context).backupSectionTitle,
-                style: Theme.of(context).textTheme.titleMedium,
-              ),
-            ],
-          ),
-          ListTile(
-            contentPadding: EdgeInsets.zero,
-            leading: const Icon(Icons.upload_outlined),
-            title: Text(AppLocalizations.of(context).backupExportTitle),
-            subtitle: Text(AppLocalizations.of(context).backupExportSubtitle),
-            onTap: () => _exportar(context),
-          ),
-          ListTile(
-            contentPadding: EdgeInsets.zero,
-            leading: const Icon(Icons.download_outlined),
-            title: Text(AppLocalizations.of(context).backupImportTitle),
-            subtitle: Text(AppLocalizations.of(context).backupImportSubtitle),
-            onTap: () => _importar(context),
-          ),
-        ],
-      ),
-    );
-  }
-}
-
-class _SeccionInfo extends StatelessWidget {
-  const _SeccionInfo();
-
-  @override
-  Widget build(BuildContext context) {
-    return Consumer<EstadoRadio>(
-      builder:
-          (ctx, estado, _) => PluriGlassSurface(
-            child: Column(
-              children: [
-                FutureBuilder<PackageInfo>(
-                  future: PackageInfo.fromPlatform(),
-                  builder: (ctx, snap) {
-                    final version =
-                        snap.hasData
-                            ? 'v${snap.data!.version}+${snap.data!.buildNumber}'
-                            : AppLocalizations.of(ctx).appVersionLoading;
-                    return ListTile(
-                      contentPadding: EdgeInsets.zero,
-                      leading: const PluriIcon(
-                        glyph: PluriIconGlyph.settings,
-                        variant: PluriIconVariant.filled,
-                      ),
-                      title: Text(AppLocalizations.of(ctx).appTitle),
-                      subtitle: Text(
-                        AppLocalizations.of(ctx).appVersionSubtitle(version),
-                      ),
-                    );
-                  },
-                ),
-                FutureBuilder<int>(
-                  future: estado.favoritos.obtenerTodos().then((l) => l.length),
-                  builder:
-                      (ctx, snap) => ListTile(
-                        contentPadding: EdgeInsets.zero,
-                        leading: const Icon(Icons.favorite_outline_rounded),
-                        title: Text(
-                          AppLocalizations.of(ctx).savedFavoritesTitle,
-                        ),
-                        trailing: Text(
-                          snap.data?.toString() ??
-                              AppLocalizations.of(ctx).dash,
-                          style: Theme.of(ctx).textTheme.bodyLarge,
-                        ),
-                      ),
-                ),
-                ListTile(
-                  contentPadding: EdgeInsets.zero,
-                  leading: const Icon(Icons.help_outline_rounded),
-                  title: Text(AppLocalizations.of(ctx).helpTitle),
-                  subtitle: Text(AppLocalizations.of(ctx).helpSubtitle),
-                  trailing: const Icon(Icons.chevron_right_rounded),
-                  onTap: () => PluriOnboardingDialog.mostrar(ctx),
-                ),
-                ListTile(
-                  contentPadding: EdgeInsets.zero,
-                  leading: const Icon(Icons.verified_outlined),
-                  title: Text(AppLocalizations.of(ctx).stationFilterTitle),
-                  subtitle: Text(
-                    AppLocalizations.of(ctx).stationFilterSubtitle,
-                  ),
-                  trailing: Icon(
-                    Icons.check_circle_rounded,
-                    color: Theme.of(ctx).colorScheme.secondary,
-                  ),
-                ),
-                ListTile(
-                  contentPadding: EdgeInsets.zero,
-                  leading: const Icon(Icons.music_note_outlined),
-                  title: Text(AppLocalizations.of(ctx).backgroundAudioTitle),
-                  subtitle: Text(
-                    AppLocalizations.of(ctx).backgroundAudioSubtitle,
-                  ),
-                  trailing: Icon(
-                    Icons.check_circle_rounded,
-                    color: Theme.of(ctx).colorScheme.secondary,
-                  ),
-                ),
-              ],
-            ),
-          ),
-    );
-  }
-}

openspec/changes/rediseno-funcional/tasks.md

@@ -39,7 +39,7 @@
 | 1 | `feat(tokens): add design tokens, type scale, push scaffold, and root nav state` | — | 220-330 | Low | No |
 | 2 | `test(auto): confirm Android Auto tree matches the redesign, no code changes` | — | 0 | None | No |
 | 3a | `refactor(ajustes): split Settings AUDIO/EMISORAS into pushed detail screens` | 1 | ~~800-1000~~ → **REALIZED: 4,374** (2,760+ / 1,614-, 35 files) | High | **Yes — move-only diff** |
-| 3b | `refactor(ajustes): split remaining Settings sections into pushed screens` | 3a | **~2,500-3,200**\* | Medium-High | **Yes — move-only diff** |
+| 3b | `refactor(ajustes): split remaining Settings sections into pushed screens` | 3a | ~~2,500-3,200~~\* → **REALIZED: 2,190** (1,485+ / 705-, 28 files) | Medium-High | **Yes — move-only diff** |
 | 4 | `feat(favoritos): replace stacked group panels with chip-filtered reorderable list` | 1 | 300-400 | Medium | Monitor |
 | 5 | `feat(escuchar): replace discovery browser with embedded player and favorites grid` | 1, 4 | 350-450 | Medium | Monitor |
 | 6 | `feat(buscar): add discovery landing state, filter pills, counter, and sort` | 5 | 350-500 | Medium-High | Monitor |
@@ -66,9 +66,10 @@ WU3b moves 5 sections rather than 7 and needs no new shared widget (`fila_ajuste
 ~2,500-3,200. **Estimating lesson for every remaining work unit: a strict-TDD commit carries its test files, and any
 ARB touch drags 13 generated files with it. Estimates that count only `lib/` production code will read ~3-4x low.**
 
-**Root line count, for reference**: `pantalla_ajustes.dart` went 1,897 → **788** in WU3a. The "under 400 lines"
-success criterion is the WU3a+WU3b **combined** end state, not WU3a alone — WU3a owns only 7 of the 12 detail
-screens. WU3b must take the remaining ~388 lines out.
+**Root line count, for reference**: `pantalla_ajustes.dart` went 1,897 → 788 in WU3a → **198** in WU3b. The "under
+400 lines" success criterion was the WU3a+WU3b **combined** end state — WU3a owned only 7 of the 12 detail screens.
+WU3b converted the remaining 5 (Grabaciones, Música local, Idioma, Backup, Info) and the root is now exactly 4
+`GrupoAjustes` cards, well under the 400-line target.
 † Record `size:exception` at apply time only if the realized diff exceeds ~500 lines; justification: "largest single
 alarm-card + hero + vacation-summary restyle, not divisible without breaking the one-commit-per-work-unit rule."
 ‡ The proposal already isolates WU10 as "its own PR, never bundled" — splitting further would leave an unintegrated
@@ -226,23 +227,45 @@ modified. Do not attempt to slice under 450.
 Backup, Info)
 **Modified tests**: `test/pantallas/pantalla_ajustes_test.dart` (extended)
 
-- [ ] 3b.1 RED — extend detail-screen tests for the remaining 5 sections, asserting `PluriPushScaffold` usage and
-      preserved controls.
-- [ ] 3b.2 GREEN — cut `_SeccionGrabaciones` (92-291), `_SeccionMusicaLocal` (291-399) into
-      `pantalla_ajustes_grabaciones.dart`, `pantalla_ajustes_musica_local.dart`.
-- [ ] 3b.3 GREEN — cut `_SeccionIdioma` + `_IdiomaDisponible` (492-694), `_SeccionBackup` (1669-1791),
-      `_SeccionInfo` (1791-1896) into `pantalla_ajustes_idioma.dart`, `pantalla_ajustes_backup.dart`,
-      `pantalla_ajustes_info.dart`.
-- [ ] 3b.4 GREEN — in the root, replace the remaining sections with `FilaAjuste` rows under two more `GrupoAjustes`
-      cards (GRABACIONES Y MÚSICA, APLICACIÓN); confirm sleep timer and backup rows are present — corollary ruling,
-      nothing dropped.
-- [ ] 3b.5 REFACTOR — confirm `pantalla_ajustes.dart` now contains only 4 `GrupoAjustes` cards and is under 400
-      lines; delete now-unused private section widgets.
-- [ ] 3b.6 Verify — full `pantalla_ajustes_test.dart` suite green; all 12 detail screens present and reachable; no
-      service/state file touched.
+- [x] 3b.1 RED — extend detail-screen tests for the remaining 5 sections, asserting `PluriPushScaffold` usage and
+      preserved controls. **Applied against the CURRENT 788-line file (re-read fresh at apply time, not the stale
+      92-1896 line references below, which were computed against the pre-WU3a 1,897-line file).** Root test file:
+      removed the now-false "Sections pending WU3b remain inline" and "Phase 7" groups, added a `WU3b — GRABACIONES Y
+      MÚSICA and APLICACIÓN groups` group (5 scenarios: 2-row/3-row zero-inline-control checks, 2 push-navigation
+      checks, one "root is exactly 4 GrupoAjustes cards" check). The 2 relocated Phase-7 friendly-folder-name
+      scenarios moved verbatim into the new `ajustes/pantalla_ajustes_musica_local_test.dart`, targeting the isolated
+      pushed screen directly instead of scrolling to find it inside the whole root.
+- [x] 3b.2 GREEN — cut `_SeccionGrabaciones`, `_SeccionMusicaLocal` (Stateful) into `pantalla_ajustes_grabaciones.dart`,
+      `pantalla_ajustes_musica_local.dart` — verbatim, header row removed per the established rule.
+- [x] 3b.3 GREEN — cut `_SeccionIdioma` + `_IdiomaDisponible`, `_SeccionBackup`, `_SeccionInfo` into
+      `pantalla_ajustes_idioma.dart`, `pantalla_ajustes_backup.dart`, `pantalla_ajustes_info.dart`. **Correction
+      found at apply time**: unlike the other 4 sections, `_SeccionInfo` never had its own header icon+title row —
+      its first tile (app name + version) already served that role — so there was no header to strip for that one
+      screen; its body moved in full, unchanged. This is also why `infoSectionTitle` is a genuinely new ARB key (no
+      existing in-body header string covered a bare "Info" label), unlike the other 4 screens which all reuse
+      pre-existing strings.
+- [x] 3b.4 GREEN — in the root, replaced the remaining 5 sections with `FilaAjuste` rows under two more
+      `GrupoAjustes` cards: RECORDINGS & MUSIC (Recordings, Local music) and APPLICATION (Language, Backup, Info).
+      Confirmed sleep timer (WU3a) and backup/restore (this WU) rows are both present — corollary ruling, nothing
+      dropped. **3 new ARB keys** (en/es only, matching WU1/WU3a's precedent of leaving the other 11 locales for
+      WU18): `settingsGroupRecordingsTitle` ("RECORDINGS & MUSIC"/"GRABACIONES Y MÚSICA"),
+      `settingsGroupApplicationTitle` ("APPLICATION"/"APLICACIÓN") for the two new group eyebrow labels, and
+      `infoSectionTitle` ("Info"/"Información") for the one row with no pre-existing header string (see 3b.3). All
+      other row titles reuse existing ARB keys.
+- [x] 3b.5 REFACTOR — confirmed `pantalla_ajustes.dart` now contains exactly 4 `GrupoAjustes` cards and is **198
+      lines** (well under the 400-line target); deleted all 5 now-unused private section widgets plus every import
+      that was only needed by their bodies (`dart:async`, `dart:io`, `file_picker`, `package_info_plus`,
+      `path_provider`, `provider`, `share_plus`, `estado_grabacion.dart`, `estado_idioma.dart`, `estado_radio.dart`,
+      `musica_local_auto.dart`, `pluri_glass_surface.dart`, `pluri_onboarding_dialog.dart` — none of these are read
+      by the root anymore since it is pure navigation chrome).
+- [x] 3b.6 Verify — scoped suite (`pantalla_ajustes_test.dart` + `ajustes/`) green: 45/45. All 12 detail screens
+      present and reachable. `git diff` touches only screen/test/ARB(+generated l10n) files — no service/state file
+      touched. Full suite: 592/592 (up from 579). `flutter analyze`: 1 issue, identical to baseline.
 
-**`size:exception` — "move-only diff".** ~500-700 changed lines (derived; see forecast table footnote). Same
-justification as WU3a.
+**`size:exception` — "move-only diff".** Realized: **2,190 changed lines** (1,485+ / 705-) across 28 files — under
+the ~2,500-3,200 estimate this time (Música local's compact Stateful body and this batch's conservative choice to
+verify reachability rather than tap through unmocked native-channel controls for Backup/Grabaciones' riskiest rows
+both kept it below forecast). Same "move-only diff" justification as WU3a.
 
 ## WU4 — Favoritos restyle
 

test/pantallas/ajustes/pantalla_ajustes_backup_test.dart

@@ -0,0 +1,109 @@
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/estado/estado_radio.dart';
+import 'package:pluriwave/l10n/gen/app_localizations.dart';
+import 'package:pluriwave/pantallas/ajustes/pantalla_ajustes_backup.dart';
+import 'package:pluriwave/widgets/pluri_push_scaffold.dart';
+import 'package:provider/provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import '../../helpers/fakes.dart';
+import '../../helpers/fakes_alarmas.dart';
+
+/// Pre-existing project constraint (see `pantalla_ajustes_test.dart`):
+/// PluriGlassSurface paints a background over ListTile's ink layer, which
+/// Flutter flags as a warning-level assertion, not a correctness bug.
+void _suppressListTileInkAssertion() {
+  final original = FlutterError.onError;
+  FlutterError.onError = (details) {
+    if (details.exceptionAsString().contains(
+      'ListTile background color or ink splashes may be invisible',
+    )) {
+      return;
+    }
+    original?.call(details);
+  };
+  addTearDown(() => FlutterError.onError = original);
+}
+
+/// WU3b task 3b.1: the APLICACIÓN detail screen for "Copia de seguridad"
+/// renders inside a [PluriPushScaffold] and its moved controls (export /
+/// import rows) are still present and reachable exactly as they were inside
+/// the old `_SeccionBackup`.
+///
+/// Both rows call into native plugins (`share_plus`, `file_picker`) that
+/// this suite does not mock, so this file verifies reachability (title and
+/// both row labels present, with a live `onTap`) rather than tapping through
+/// the native share/pick flow — the same conservative choice this batch
+/// makes for any moved control that would otherwise depend on an unmocked
+/// platform channel.
+void main() {
+  setUp(() {
+    SharedPreferences.setMockInitialValues({});
+  });
+
+  Future<File> archivoCustomVacio() async => File(
+    '${Directory.current.path}/test/fixtures/emisoras_custom_vacio.json',
+  );
+
+  Future<EstadoRadio> crearEstado() async {
+    return EstadoRadio(
+      audio: FakeServicioAudio(),
+      favoritos: FakeServicioFavoritos(),
+      radio: FakeServicioRadio(),
+      servicioEcualizador: FakeServicioEcualizador(),
+      servicioGrabacion: FakeServicioGrabacionRadioInactiva(),
+      resolverArchivoCustom: archivoCustomVacio,
+      iniciarAutomaticamente: false,
+    );
+  }
+
+  Widget buildScreen(EstadoRadio estado) {
+    return ChangeNotifierProvider<EstadoRadio>.value(
+      value: estado,
+      child: MaterialApp(
+        locale: const Locale('en'),
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        home: const PantallaAjustesBackup(),
+      ),
+    );
+  }
+
+  testWidgets('renders inside a PluriPushScaffold titled "Backup"', (
+    tester,
+  ) async {
+    _suppressListTileInkAssertion();
+    final estado = await crearEstado();
+    addTearDown(estado.dispose);
+
+    await tester.pumpWidget(buildScreen(estado));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(find.byType(PluriPushScaffold), findsOneWidget);
+    expect(find.text('Backup'), findsOneWidget);
+  });
+
+  testWidgets(
+    'moved controls still reachable: export and import rows both present',
+    (tester) async {
+      _suppressListTileInkAssertion();
+      final estado = await crearEstado();
+      addTearDown(estado.dispose);
+
+      await tester.pumpWidget(buildScreen(estado));
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 100));
+
+      final exportTile = find.widgetWithText(ListTile, 'Export configuration');
+      final importTile = find.widgetWithText(ListTile, 'Import configuration');
+      expect(exportTile, findsOneWidget);
+      expect(importTile, findsOneWidget);
+      expect(tester.widget<ListTile>(exportTile).onTap, isNotNull);
+      expect(tester.widget<ListTile>(importTile).onTap, isNotNull);
+    },
+  );
+}

test/pantallas/ajustes/pantalla_ajustes_grabaciones_test.dart

@@ -0,0 +1,103 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/estado/estado_grabacion.dart';
+import 'package:pluriwave/l10n/gen/app_localizations.dart';
+import 'package:pluriwave/pantallas/ajustes/pantalla_ajustes_grabaciones.dart';
+import 'package:pluriwave/widgets/pluri_push_scaffold.dart';
+import 'package:provider/provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import '../../helpers/fakes_alarmas.dart';
+
+/// Pre-existing project constraint (see `pantalla_ajustes_test.dart`):
+/// PluriGlassSurface paints a background over ListTile's ink layer, which
+/// Flutter flags as a warning-level assertion, not a correctness bug.
+void _suppressListTileInkAssertion() {
+  final original = FlutterError.onError;
+  FlutterError.onError = (details) {
+    if (details.exceptionAsString().contains(
+      'ListTile background color or ink splashes may be invisible',
+    )) {
+      return;
+    }
+    original?.call(details);
+  };
+  addTearDown(() => FlutterError.onError = original);
+}
+
+/// WU3b task 3b.1: the GRABACIONES Y MÚSICA detail screen for "Grabaciones"
+/// renders inside a [PluriPushScaffold] and its moved controls still respond
+/// exactly as they did inside the old `_SeccionGrabaciones`.
+///
+/// This file deliberately does NOT interact with "Maximum recording size"
+/// (`_editarTamanoMaximo`): that control has a pre-existing, out-of-scope
+/// controller-dispose race (documented in `pantalla_ajustes_grabaciones.dart`
+/// and, for the analogous `_editarGrupo` case, in
+/// `pantalla_ajustes_grupos_favoritos_test.dart`) that this move does not
+/// fix. "Restore default path" is exercised instead — a real, moved
+/// capability with no such hazard.
+void main() {
+  setUp(() {
+    SharedPreferences.setMockInitialValues({});
+  });
+
+  Widget buildScreen(EstadoGrabacion estado) {
+    return ListenableProvider<EstadoGrabacion>.value(
+      value: estado,
+      child: MaterialApp(
+        locale: const Locale('en'),
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        home: const PantallaAjustesGrabaciones(),
+      ),
+    );
+  }
+
+  testWidgets('renders inside a PluriPushScaffold titled "Recordings"', (
+    tester,
+  ) async {
+    _suppressListTileInkAssertion();
+    final estado = EstadoGrabacion(
+      servicio: FakeServicioGrabacionRadioInactiva(),
+    );
+    addTearDown(estado.dispose);
+
+    await tester.pumpWidget(buildScreen(estado));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(find.byType(PluriPushScaffold), findsOneWidget);
+    expect(find.text('Recordings'), findsOneWidget);
+  });
+
+  testWidgets('moved control still responds: restore default path clears the '
+      'configured directory', (tester) async {
+    _suppressListTileInkAssertion();
+    final estado = EstadoGrabacion(
+      servicio: FakeServicioGrabacionRadioInactiva(),
+    );
+    addTearDown(estado.dispose);
+    await estado.cambiarDirectorio('/tmp/custom-recordings');
+    expect(estado.directorioConfigurado, '/tmp/custom-recordings');
+
+    await tester.pumpWidget(buildScreen(estado));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    await tester.tap(find.byIcon(Icons.restore_rounded));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(estado.directorioConfigurado, isNull);
+    expect(
+      find.text('The default internal folder will be used'),
+      findsOneWidget,
+    );
+
+    // SnackBar's own dismiss Timer is not frame-scheduled — let it resolve
+    // before teardown (WU3a batch discovery) instead of leaving a pending
+    // Timer behind.
+    await tester.pump(const Duration(seconds: 5));
+    await tester.pumpAndSettle();
+  });
+}

test/pantallas/ajustes/pantalla_ajustes_idioma_test.dart

@@ -0,0 +1,72 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/estado/estado_idioma.dart';
+import 'package:pluriwave/l10n/gen/app_localizations.dart';
+import 'package:pluriwave/pantallas/ajustes/pantalla_ajustes_idioma.dart';
+import 'package:pluriwave/widgets/pluri_push_scaffold.dart';
+import 'package:provider/provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// WU3b task 3b.1: the APLICACIÓN detail screen for "Idioma" renders inside
+/// a [PluriPushScaffold] and its moved control (the language dropdown)
+/// still responds exactly as it did inside the old `_SeccionIdioma`.
+void main() {
+  setUp(() {
+    SharedPreferences.setMockInitialValues({});
+  });
+
+  Widget buildScreen(EstadoIdioma estado) {
+    return ChangeNotifierProvider<EstadoIdioma>.value(
+      value: estado,
+      child: MaterialApp(
+        locale: const Locale('en'),
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        home: const PantallaAjustesIdioma(),
+      ),
+    );
+  }
+
+  testWidgets('renders inside a PluriPushScaffold titled "Language"', (
+    tester,
+  ) async {
+    final estado = EstadoIdioma(
+      sharedPreferences: await SharedPreferences.getInstance(),
+    );
+    addTearDown(estado.dispose);
+
+    await tester.pumpWidget(buildScreen(estado));
+    await tester.pumpAndSettle();
+
+    expect(find.byType(PluriPushScaffold), findsOneWidget);
+    // "Language" legitimately renders twice here too (pre-existing,
+    // unmodified by this move): the pushed screen's title AND the
+    // dropdown's own floating label share the same l10n string.
+    expect(find.text('Language'), findsWidgets);
+  });
+
+  testWidgets('moved control still responds: selecting a language persists '
+      'it', (tester) async {
+    final estado = EstadoIdioma(
+      sharedPreferences: await SharedPreferences.getInstance(),
+    );
+    addTearDown(estado.dispose);
+
+    await tester.pumpWidget(buildScreen(estado));
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.byType(DropdownButtonFormField<String>));
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('Español').last);
+    await tester.pumpAndSettle();
+
+    expect(estado.localeSeleccionado, const Locale('es'));
+    expect(find.text('Language updated: Español'), findsOneWidget);
+
+    // SnackBar's own dismiss Timer is not frame-scheduled — let it resolve
+    // before teardown (WU3a batch discovery) instead of leaving a pending
+    // Timer behind.
+    await tester.pump(const Duration(seconds: 5));
+    await tester.pumpAndSettle();
+  });
+}

test/pantallas/ajustes/pantalla_ajustes_info_test.dart

@@ -0,0 +1,101 @@
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/estado/estado_radio.dart';
+import 'package:pluriwave/l10n/gen/app_localizations.dart';
+import 'package:pluriwave/pantallas/ajustes/pantalla_ajustes_info.dart';
+import 'package:pluriwave/widgets/pluri_push_scaffold.dart';
+import 'package:provider/provider.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+import '../../helpers/fakes.dart';
+import '../../helpers/fakes_alarmas.dart';
+
+/// Pre-existing project constraint (see `pantalla_ajustes_test.dart`):
+/// PluriGlassSurface paints a background over ListTile's ink layer, which
+/// Flutter flags as a warning-level assertion, not a correctness bug.
+void _suppressListTileInkAssertion() {
+  final original = FlutterError.onError;
+  FlutterError.onError = (details) {
+    if (details.exceptionAsString().contains(
+      'ListTile background color or ink splashes may be invisible',
+    )) {
+      return;
+    }
+    original?.call(details);
+  };
+  addTearDown(() => FlutterError.onError = original);
+}
+
+/// WU3b task 3b.1: the APLICACIÓN detail screen for "Info" renders inside a
+/// [PluriPushScaffold] and its moved controls (saved-favorites count, help
+/// row) still respond exactly as they did inside the old `_SeccionInfo`.
+/// Unlike the other four WU3b screens, this one never had its own header
+/// icon+title row to strip (see `pantalla_ajustes_info.dart`'s doc comment).
+void main() {
+  setUp(() {
+    SharedPreferences.setMockInitialValues({});
+  });
+
+  Future<File> archivoCustomVacio() async => File(
+    '${Directory.current.path}/test/fixtures/emisoras_custom_vacio.json',
+  );
+
+  Future<EstadoRadio> crearEstado() async {
+    return EstadoRadio(
+      audio: FakeServicioAudio(),
+      favoritos: FakeServicioFavoritos(),
+      radio: FakeServicioRadio(),
+      servicioEcualizador: FakeServicioEcualizador(),
+      servicioGrabacion: FakeServicioGrabacionRadioInactiva(),
+      resolverArchivoCustom: archivoCustomVacio,
+      iniciarAutomaticamente: false,
+    );
+  }
+
+  Widget buildScreen(EstadoRadio estado) {
+    return ChangeNotifierProvider<EstadoRadio>.value(
+      value: estado,
+      child: MaterialApp(
+        locale: const Locale('en'),
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        home: const PantallaAjustesInfo(),
+      ),
+    );
+  }
+
+  testWidgets('renders inside a PluriPushScaffold titled "Info"', (
+    tester,
+  ) async {
+    _suppressListTileInkAssertion();
+    final estado = await crearEstado();
+    addTearDown(estado.dispose);
+
+    await tester.pumpWidget(buildScreen(estado));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(find.byType(PluriPushScaffold), findsOneWidget);
+    expect(find.text('Info'), findsOneWidget);
+  });
+
+  testWidgets(
+    'moved control still responds: saved favorites count reflects the '
+    'favorites list',
+    (tester) async {
+      _suppressListTileInkAssertion();
+      final estado = await crearEstado();
+      addTearDown(estado.dispose);
+
+      await tester.pumpWidget(buildScreen(estado));
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 100));
+
+      expect(find.text('Saved favorites'), findsOneWidget);
+      expect(find.text('0'), findsOneWidget);
+      expect(find.text('Help and tutorial'), findsOneWidget);
+    },
+  );
+}

test/pantallas/ajustes/pantalla_ajustes_musica_local_test.dart

@@ -0,0 +1,68 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/l10n/gen/app_localizations.dart';
+import 'package:pluriwave/pantallas/ajustes/pantalla_ajustes_musica_local.dart';
+import 'package:pluriwave/widgets/pluri_push_scaffold.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+/// WU3b task 3b.1: the GRABACIONES Y MÚSICA detail screen for "Música local"
+/// renders inside a [PluriPushScaffold] and its moved controls (the
+/// android-auto-local-music-paging Phase 7 friendly-folder-name projection)
+/// still respond exactly as they did inside the old `_SeccionMusicaLocal`.
+///
+/// The two Phase 7 scenarios below are relocated verbatim from
+/// `pantalla_ajustes_test.dart`'s "_SeccionMusicaLocal — friendly folder
+/// name (Phase 7)" group, now targeting the isolated screen directly instead
+/// of scrolling to find it inside the whole Settings root.
+void main() {
+  Widget buildScreen() {
+    return const MaterialApp(
+      locale: Locale('en'),
+      localizationsDelegates: AppLocalizations.localizationsDelegates,
+      supportedLocales: AppLocalizations.supportedLocales,
+      home: PantallaAjustesMusicaLocal(),
+    );
+  }
+
+  testWidgets('renders inside a PluriPushScaffold titled "Local music (Android '
+      'Auto)"', (tester) async {
+    SharedPreferences.setMockInitialValues({});
+
+    await tester.pumpWidget(buildScreen());
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(find.byType(PluriPushScaffold), findsOneWidget);
+    expect(find.text('Local music (Android Auto)'), findsOneWidget);
+  });
+
+  testWidgets(
+    '7.1-A: carpeta configurada muestra el nombre amigable derivado de la '
+    'URI, nunca la URI cruda',
+    (tester) async {
+      SharedPreferences.setMockInitialValues({
+        'musica_local_uri':
+            'content://com.android.externalstorage.documents/tree/'
+            'primary%3AMusic%2FMyFolder',
+      });
+
+      await tester.pumpWidget(buildScreen());
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 100));
+
+      expect(find.text('MyFolder'), findsOneWidget);
+      expect(find.textContaining('content://'), findsNothing);
+    },
+  );
+
+  testWidgets('7.1-B: sin carpeta configurada mantiene el mensaje '
+      'localMusicFolderNotConfigured', (tester) async {
+    SharedPreferences.setMockInitialValues({});
+
+    await tester.pumpWidget(buildScreen());
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(find.text('No folder selected'), findsOneWidget);
+  });
+}

test/pantallas/pantalla_ajustes_test.dart

@@ -88,15 +88,12 @@ void main() {
 
   // ── WU3a: AUDIO + EMISORAS become grouped nav rows ─────────────────────────
   //
-  // Design ADR-3: the root now carries zero inline controls for the 7
-  // sections WU3a moved (Ecualizador, Salida de audio, Temporizador de sueño,
-  // Grupos de favoritos, Emisora preferida, Emisoras personalizadas, Orden de
-  // listas) — each is reached through a FilaAjuste row instead. The other 5
-  // sections (Grabaciones, Música local, Idioma, Backup, Info) still render
-  // inline here: WU3b decomposes GRABACIONES Y MÚSICA / APLICACIÓN the same
-  // way, so the root is not yet under 400 lines nor fully "zero inline
-  // controls" — that end state is WU3b's completion, not WU3a's (see the
-  // apply-progress note on this discrepancy in tasks.md 3a.1/3a.8).
+  // Design ADR-3: the root carries zero inline controls for the 7 sections
+  // WU3a moved (Ecualizador, Salida de audio, Temporizador de sueño, Grupos
+  // de favoritos, Emisora preferida, Emisoras personalizadas, Orden de
+  // listas) — each is reached through a FilaAjuste row instead. WU3b (below)
+  // completes the remaining 5 sections, so the root is now exactly 4
+  // GrupoAjustes cards, under 400 lines.
   group('WU3a — AUDIO and EMISORAS groups', () {
     testWidgets('AUDIO group renders exactly 3 nav rows, no inline controls', (
       tester,
@@ -190,9 +187,66 @@ void main() {
     });
   });
 
-  // ── Sections not yet converted (WU3b's job) stay reachable ─────────────────
-  group('Sections pending WU3b remain inline and reachable', () {
-    testWidgets('Grabaciones, Idioma, Backup and Info still render', (
+  // ── WU3b: GRABACIONES Y MÚSICA + APLICACIÓN become grouped nav rows ───────
+  //
+  // Design ADR-3: the root now carries zero inline controls for the final 5
+  // sections (Grabaciones, Música local, Idioma, Backup, Info) — each is
+  // reached through a FilaAjuste row, matching WU3a's AUDIO/EMISORAS
+  // treatment. All 12 sections are decomposed now; the root is exactly 4
+  // GrupoAjustes cards and crosses under 400 lines (tasks.md 3b.5). The two
+  // "Phase 7" friendly-folder-name scenarios that used to live in this file
+  // are relocated verbatim to `ajustes/pantalla_ajustes_musica_local_test.dart`,
+  // now targeting the isolated pushed screen directly.
+  group('WU3b — GRABACIONES Y MÚSICA and APLICACIÓN groups', () {
+    testWidgets(
+      'RECORDINGS & MUSIC group renders exactly 2 nav rows, no inline '
+      'controls',
+      (tester) async {
+        setLargeSurface(tester);
+        _suppressListTileInkAssertion();
+        final estado = await crearEstado();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildAjustes(estado));
+        await pumpStable(tester);
+
+        expect(find.text('RECORDINGS & MUSIC'), findsOneWidget);
+        expect(find.text('Recordings'), findsOneWidget);
+        expect(find.text('Local music (Android Auto)'), findsOneWidget);
+
+        // Zero inline controls: the folder-path row, path action buttons and
+        // max-size row are gone from the root now.
+        expect(find.text('Change path'), findsNothing);
+        expect(find.text('Maximum recording size'), findsNothing);
+      },
+    );
+
+    testWidgets(
+      'APPLICATION group renders exactly 3 nav rows, no inline controls',
+      (tester) async {
+        setLargeSurface(tester);
+        _suppressListTileInkAssertion();
+        final estado = await crearEstado();
+        addTearDown(estado.dispose);
+
+        await tester.pumpWidget(buildAjustes(estado));
+        await pumpStable(tester);
+
+        expect(find.text('APPLICATION'), findsOneWidget);
+        // "Language" now renders exactly once at the root (the FilaAjuste
+        // row only) — the old inline dropdown's duplicate label is gone.
+        expect(find.text('Language'), findsOneWidget);
+        expect(find.text('Backup'), findsOneWidget);
+        expect(find.text('Info'), findsOneWidget);
+
+        // Zero inline controls: the language dropdown and export/import rows
+        // are gone from the root now.
+        expect(find.byType(DropdownButtonFormField<String>), findsNothing);
+        expect(find.text('Export configuration'), findsNothing);
+      },
+    );
+
+    testWidgets('tapping the Grabaciones row pushes its detail screen', (
       tester,
     ) async {
       setLargeSurface(tester);
@@ -203,50 +257,16 @@ void main() {
       await tester.pumpWidget(buildAjustes(estado));
       await pumpStable(tester);
 
-      expect(find.text('Recordings'), findsOneWidget);
-      // "Language" legitimately renders twice (pre-existing, unmodified by
-      // WU3a): the section header AND the dropdown's own label share the
-      // same l10n string.
-      expect(find.text('Language'), findsWidgets);
-      expect(find.text('Backup'), findsOneWidget);
-      expect(find.text('Help and tutorial'), findsOneWidget);
+      await tester.tap(find.text('Recordings'));
+      await pumpStable(tester);
+
+      expect(find.byType(PluriPushScaffold), findsOneWidget);
+      expect(find.text('Change path'), findsOneWidget);
     });
-  });
 
-  // ── android-auto-local-music-paging Phase 7: friendly folder name ────────
-  group('_SeccionMusicaLocal — friendly folder name (Phase 7)', () {
-    testWidgets(
-      '7.1-A: carpeta configurada muestra el nombre amigable derivado de '
-      'la URI, nunca la URI cruda',
-      (tester) async {
-        SharedPreferences.setMockInitialValues({
-          'musica_local_uri':
-              'content://com.android.externalstorage.documents/tree/'
-              'primary%3AMusic%2FMyFolder',
-        });
-        setLargeSurface(tester);
-        _suppressListTileInkAssertion();
-        final estado = await crearEstado();
-        addTearDown(estado.dispose);
-
-        await tester.pumpWidget(buildAjustes(estado));
-        await pumpStable(tester);
-
-        await tester.scrollUntilVisible(
-          find.text('Local music folder'),
-          300,
-          scrollable: find.byType(Scrollable).first,
-        );
-        await pumpStable(tester);
-
-        expect(find.text('MyFolder'), findsOneWidget);
-        expect(find.textContaining('content://'), findsNothing);
-      },
-    );
-
-    testWidgets('7.1-B: sin carpeta configurada mantiene el mensaje '
-        'localMusicFolderNotConfigured', (tester) async {
-      SharedPreferences.setMockInitialValues({});
+    testWidgets('tapping the Info row pushes its detail screen', (
+      tester,
+    ) async {
       setLargeSurface(tester);
       _suppressListTileInkAssertion();
       final estado = await crearEstado();
@@ -255,14 +275,28 @@ void main() {
       await tester.pumpWidget(buildAjustes(estado));
       await pumpStable(tester);
 
-      await tester.scrollUntilVisible(
-        find.text('Local music folder'),
-        300,
-        scrollable: find.byType(Scrollable).first,
-      );
+      await tester.tap(find.text('Info'));
       await pumpStable(tester);
 
-      expect(find.text('No folder selected'), findsOneWidget);
+      expect(find.byType(PluriPushScaffold), findsOneWidget);
+      expect(find.text('Help and tutorial'), findsOneWidget);
+    });
+
+    testWidgets('root now contains exactly 4 GrupoAjustes cards', (
+      tester,
+    ) async {
+      setLargeSurface(tester);
+      _suppressListTileInkAssertion();
+      final estado = await crearEstado();
+      addTearDown(estado.dispose);
+
+      await tester.pumpWidget(buildAjustes(estado));
+      await pumpStable(tester);
+
+      expect(find.text('AUDIO'), findsOneWidget);
+      expect(find.text('STATIONS'), findsOneWidget);
+      expect(find.text('RECORDINGS & MUSIC'), findsOneWidget);
+      expect(find.text('APPLICATION'), findsOneWidget);
     });
   });
 }