feat(i18n): add redesign strings and translate Escuchar rename to 11 locales

test/l10n/arb_test_helpers.dart

@@ -0,0 +1,36 @@
+import 'dart:convert';
+import 'dart:io';
+
+/// All 13 supported locale codes backing `lib/l10n/app_*.arb`.
+///
+/// `flutter test` always runs with the working directory set to the
+/// package root, so `lib/l10n/...` below resolves correctly without any
+/// extra path juggling.
+const List<String> supportedArbLocales = [
+  'ar',
+  'bn',
+  'de',
+  'en',
+  'es',
+  'fr',
+  'hi',
+  'id',
+  'it',
+  'ja',
+  'pt',
+  'ru',
+  'zh',
+];
+
+/// Reads and decodes `lib/l10n/app_<locale>.arb` as a JSON map.
+Map<String, dynamic> readArb(String locale) {
+  final file = File('lib/l10n/app_$locale.arb');
+  return json.decode(file.readAsStringSync()) as Map<String, dynamic>;
+}
+
+/// Real translation keys only -- excludes ICU metadata entries (`@key`)
+/// and the `@@locale` marker, which are not themselves translatable
+/// strings.
+Set<String> realKeys(Map<String, dynamic> arb) {
+  return arb.keys.where((key) => !key.startsWith('@')).toSet();
+}