fix(bienvenida,grabaciones): headline size, CTA radius, storage caption

Screen 14 / audit 14.3+14.7: welcome headline now 34px/ls-1.2 (was
headlineMedium's 28/ls-1.0), CTA restyled to a radius-18 rounded
rectangle instead of Material 3's default StadiumBorder (t4:696,715).

Screen 12 / audit 12.2+12.3: the recordings storage card now shows the
bold "X of Y used" headline ABOVE a 6px/radius-3 bar, followed by a
real folder-path + purge-policy caption below it -- was the bar first
with the "used" string as its only (small, generic) caption (t4:613).
New ARB key recordingsLibraryStorageFolderCaption, translated to all
13 locales.

Item 12.5 (folder/max-size settings living behind the header action
instead of inline on this screen) is a deliberate structural split
from WU15b; the audit itself scopes it out of this pass.

lib/l10n/gen/app_localizations_es.dart

@@ -447,6 +447,10 @@ class AppLocalizationsEs extends AppLocalizations {
     return '$usedMb MB de $totalMb MB usados';
   }
 
+  @override
+  String get recordingsLibraryStorageFolderCaption =>
+      'Music/PluriWave · se borran las más antiguas al llegar al límite';
+
   @override
   String get recordingsLibraryEmptyTitle => 'Todavía no hay grabaciones';
 
@@ -620,12 +624,20 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get searchMinQualityFilterLabel => 'Calidad mínima';
 
+  @override
+  String get searchLoadingStationsLabel => 'BUSCANDO EMISORAS…';
+
   @override
   String get searchEmptyTitle => 'Buscá una emisora';
 
   @override
   String get searchNoResultsTitle => 'Sin resultados';
 
+  @override
+  String searchNoResultsForQueryTitle(Object query) {
+    return 'Sin resultados para «$query»';
+  }
+
   @override
   String get searchEmptySubtitle =>
       'Usá la barra superior o los chips para descubrir señales de todo el mundo.';
@@ -659,6 +671,9 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get countriesScreenTitle => 'Países';
 
+  @override
+  String get countriesSearchHint => 'País o código...';
+
   @override
   String get countriesYourLanguagesTitle => 'Tus idiomas';
 
@@ -1019,6 +1034,9 @@ class AppLocalizationsEs extends AppLocalizations {
     return '$minutes min';
   }
 
+  @override
+  String get alarmSnoozeUsualLabel => 'habitual';
+
   @override
   String get saveFavoritesAlarmHint =>
       'Guardá emisoras en Favoritos para usarlas como alarma musical.';
@@ -1362,6 +1380,9 @@ class AppLocalizationsEs extends AppLocalizations {
     return 'Días: $days';
   }
 
+  @override
+  String get alarmRepeatSectionLabel => 'REPETIR';
+
   @override
   String get androidReliabilityTitle => 'Revisar fiabilidad Android';