fix(buscar): build the 2x2 "Explorar por" grid, add Novedades

Audit 3.2 (t4 lines 162-171): the prototype groups Países, Géneros,
Tendencias and the entirely-missing Novedades into one 2x2 entry-point
grid. The build had them as three unrelated always-visible widgets
(a Países ListTile, a Géneros FilterChip Wrap, a Tendencias ActionChip
strip) and no Novedades entry at all.

Replaces all three with a single grid section, capability-preserving:
Países still pushes PantallaPaises; Géneros and Tendencias now open
their exact existing content in a picker sheet instead of always-on-
screen (Géneros auto-closes on selection, matching this screen's other
single-choice filter sheets; Tendencias stays open, a browse list, not
a filter). Novedades re-triggers the existing discovery refresh, since
no distinct "new stations" feed exists anywhere in the domain.

New ARB key set (exploreByTitle/exploreTrendingTitle/
exploreTrendingSubtitle/exploreNewTitle/exploreNewSubtitle) translated
across all 13 locales with zero anti-copy allowlist entries needed.

Also fixes a pre-existing PluriEmptyState overflow this restructure
exposed (unrelated to the grid itself, confirmed via isolated repro):
wraps its Column in a SingleChildScrollView so a too-tall title/
subtitle scrolls instead of throwing a hard RenderFlex overflow.

lib/l10n/gen/app_localizations.dart

@@ -1438,6 +1438,36 @@ abstract class AppLocalizations {
   /// **'Géneros'**
   String get genresTitle;
 
+  /// No description provided for @exploreByTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Explorar por'**
+  String get exploreByTitle;
+
+  /// No description provided for @exploreTrendingTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Tendencias'**
+  String get exploreTrendingTitle;
+
+  /// No description provided for @exploreTrendingSubtitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Hoy'**
+  String get exploreTrendingSubtitle;
+
+  /// No description provided for @exploreNewTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Novedades'**
+  String get exploreNewTitle;
+
+  /// No description provided for @exploreNewSubtitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Esta semana'**
+  String get exploreNewSubtitle;
+
   /// No description provided for @offlineBannerTitle.
   ///
   /// In es, this message translates to:

lib/l10n/gen/app_localizations_ar.dart

@@ -766,6 +766,21 @@ class AppLocalizationsAr extends AppLocalizations {
   @override
   String get genresTitle => 'الأنواع';
 
+  @override
+  String get exploreByTitle => 'استكشاف حسب';
+
+  @override
+  String get exploreTrendingTitle => 'الرائجة';
+
+  @override
+  String get exploreTrendingSubtitle => 'اليوم';
+
+  @override
+  String get exploreNewTitle => 'جديد';
+
+  @override
+  String get exploreNewSubtitle => 'هذا الأسبوع';
+
   @override
   String get offlineBannerTitle => 'لا يوجد اتصال';
 

lib/l10n/gen/app_localizations_bn.dart

@@ -769,6 +769,21 @@ class AppLocalizationsBn extends AppLocalizations {
   @override
   String get genresTitle => 'ধরন';
 
+  @override
+  String get exploreByTitle => 'যেভাবে অন্বেষণ করুন';
+
+  @override
+  String get exploreTrendingTitle => 'ট্রেন্ডিং';
+
+  @override
+  String get exploreTrendingSubtitle => 'আজ';
+
+  @override
+  String get exploreNewTitle => 'নতুন';
+
+  @override
+  String get exploreNewSubtitle => 'এই সপ্তাহে';
+
   @override
   String get offlineBannerTitle => 'সংযোগ নেই';
 

lib/l10n/gen/app_localizations_de.dart

@@ -772,6 +772,21 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get genresTitle => 'Genres';
 
+  @override
+  String get exploreByTitle => 'Entdecken nach';
+
+  @override
+  String get exploreTrendingTitle => 'Trends';
+
+  @override
+  String get exploreTrendingSubtitle => 'Heute';
+
+  @override
+  String get exploreNewTitle => 'Neuheiten';
+
+  @override
+  String get exploreNewSubtitle => 'Diese Woche';
+
   @override
   String get offlineBannerTitle => 'Keine Verbindung';
 

lib/l10n/gen/app_localizations_en.dart

@@ -765,6 +765,21 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get genresTitle => 'Genres';
 
+  @override
+  String get exploreByTitle => 'Browse by';
+
+  @override
+  String get exploreTrendingTitle => 'Trending';
+
+  @override
+  String get exploreTrendingSubtitle => 'Today';
+
+  @override
+  String get exploreNewTitle => 'New';
+
+  @override
+  String get exploreNewSubtitle => 'This week';
+
   @override
   String get offlineBannerTitle => 'No connection';
 

lib/l10n/gen/app_localizations_es.dart

@@ -770,6 +770,21 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get genresTitle => 'Géneros';
 
+  @override
+  String get exploreByTitle => 'Explorar por';
+
+  @override
+  String get exploreTrendingTitle => 'Tendencias';
+
+  @override
+  String get exploreTrendingSubtitle => 'Hoy';
+
+  @override
+  String get exploreNewTitle => 'Novedades';
+
+  @override
+  String get exploreNewSubtitle => 'Esta semana';
+
   @override
   String get offlineBannerTitle => 'Sin conexión';
 

lib/l10n/gen/app_localizations_fr.dart

@@ -774,6 +774,21 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get genresTitle => 'Genres';
 
+  @override
+  String get exploreByTitle => 'Explorer par';
+
+  @override
+  String get exploreTrendingTitle => 'Tendances';
+
+  @override
+  String get exploreTrendingSubtitle => 'Aujourd\'hui';
+
+  @override
+  String get exploreNewTitle => 'Nouveautés';
+
+  @override
+  String get exploreNewSubtitle => 'Cette semaine';
+
   @override
   String get offlineBannerTitle => 'Aucune connexion';
 

lib/l10n/gen/app_localizations_hi.dart

@@ -766,6 +766,21 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get genresTitle => 'शैलियाँ';
 
+  @override
+  String get exploreByTitle => 'इस अनुसार खोजें';
+
+  @override
+  String get exploreTrendingTitle => 'ट्रेंडिंग';
+
+  @override
+  String get exploreTrendingSubtitle => 'आज';
+
+  @override
+  String get exploreNewTitle => 'नया';
+
+  @override
+  String get exploreNewSubtitle => 'इस सप्ताह';
+
   @override
   String get offlineBannerTitle => 'कोई कनेक्शन नहीं';
 

lib/l10n/gen/app_localizations_id.dart

@@ -766,6 +766,21 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get genresTitle => 'Genre';
 
+  @override
+  String get exploreByTitle => 'Jelajahi berdasarkan';
+
+  @override
+  String get exploreTrendingTitle => 'Tren';
+
+  @override
+  String get exploreTrendingSubtitle => 'Hari ini';
+
+  @override
+  String get exploreNewTitle => 'Baru';
+
+  @override
+  String get exploreNewSubtitle => 'Minggu ini';
+
   @override
   String get offlineBannerTitle => 'Tidak ada koneksi';
 

lib/l10n/gen/app_localizations_it.dart

@@ -772,6 +772,21 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get genresTitle => 'Generi';
 
+  @override
+  String get exploreByTitle => 'Esplora per';
+
+  @override
+  String get exploreTrendingTitle => 'Tendenze';
+
+  @override
+  String get exploreTrendingSubtitle => 'Oggi';
+
+  @override
+  String get exploreNewTitle => 'Novità';
+
+  @override
+  String get exploreNewSubtitle => 'Questa settimana';
+
   @override
   String get offlineBannerTitle => 'Nessuna connessione';
 

lib/l10n/gen/app_localizations_ja.dart

@@ -740,6 +740,21 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get genresTitle => 'ジャンル';
 
+  @override
+  String get exploreByTitle => 'カテゴリで探す';
+
+  @override
+  String get exploreTrendingTitle => 'トレンド';
+
+  @override
+  String get exploreTrendingSubtitle => '今日';
+
+  @override
+  String get exploreNewTitle => '新着';
+
+  @override
+  String get exploreNewSubtitle => '今週';
+
   @override
   String get offlineBannerTitle => '接続なし';
 

lib/l10n/gen/app_localizations_pt.dart

@@ -769,6 +769,21 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get genresTitle => 'Gêneros';
 
+  @override
+  String get exploreByTitle => 'Navegar por';
+
+  @override
+  String get exploreTrendingTitle => 'Tendências';
+
+  @override
+  String get exploreTrendingSubtitle => 'Hoje';
+
+  @override
+  String get exploreNewTitle => 'Novidades';
+
+  @override
+  String get exploreNewSubtitle => 'Nesta semana';
+
   @override
   String get offlineBannerTitle => 'Sem conexão';
 

lib/l10n/gen/app_localizations_ru.dart

@@ -770,6 +770,21 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get genresTitle => 'Жанры';
 
+  @override
+  String get exploreByTitle => 'Обзор по';
+
+  @override
+  String get exploreTrendingTitle => 'В тренде';
+
+  @override
+  String get exploreTrendingSubtitle => 'Сегодня';
+
+  @override
+  String get exploreNewTitle => 'Новинки';
+
+  @override
+  String get exploreNewSubtitle => 'На этой неделе';
+
   @override
   String get offlineBannerTitle => 'Нет подключения';
 

lib/l10n/gen/app_localizations_zh.dart

@@ -737,6 +737,21 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get genresTitle => '类型';
 
+  @override
+  String get exploreByTitle => '浏览分类';
+
+  @override
+  String get exploreTrendingTitle => '热门';
+
+  @override
+  String get exploreTrendingSubtitle => '今天';
+
+  @override
+  String get exploreNewTitle => '最新';
+
+  @override
+  String get exploreNewSubtitle => '本周';
+
   @override
   String get offlineBannerTitle => '无连接';