fix(paywall): add dismiss controls and honest premium copy

The premium sheet had no close affordance or way to defer, and its
copy only said "Función Premium" without stating what it unlocks.
Adds a header close (X) button and a "not now" secondary action so
dismissal is never harder than purchasing, and replaces the bare
title with a concrete, honest breakdown of the 5 things premium
unlocks (no ads, Android Auto, station recording, alarm vacation
ranges, unlimited alarms) plus the one-time-purchase framing. The
phone equalizer is never listed, since it stays free for everyone.
New l10n keys added to all 13 locales.

lib/l10n/gen/app_localizations_hi.dart

@@ -1867,4 +1867,30 @@ class AppLocalizationsHi extends AppLocalizations {
 
   @override
   String get premiumActivo => 'प्रीमियम सक्रिय';
+
+  @override
+  String get premiumHojaTitulo => 'PluriWave Premium अनलॉक करें';
+
+  @override
+  String get premiumBeneficioSinAnuncios => 'पूरे ऐप में कोई विज्ञापन नहीं';
+
+  @override
+  String get premiumBeneficioAndroidAuto => 'Android Auto';
+
+  @override
+  String get premiumBeneficioGrabacion => 'स्टेशन रिकॉर्डिंग';
+
+  @override
+  String get premiumBeneficioVacaciones => 'अलार्म के लिए छुट्टी की अवधि';
+
+  @override
+  String get premiumBeneficioAlarmasIlimitadas =>
+      'असीमित अलार्म (मुफ़्त प्लान में अधिकतम 5 की अनुमति है)';
+
+  @override
+  String get premiumPagoUnico =>
+      'एकमुश्त भुगतान, हमेशा के लिए। यह सदस्यता नहीं है।';
+
+  @override
+  String get premiumAhoraNo => 'अभी नहीं';
 }