fix(ui): update tutorial copy and library play button

test/tutorial_copy_test.dart

@@ -0,0 +1,41 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:spotiflac_android/l10n/app_localizations.dart';
+
+void main() {
+  group('setup and tutorial copy', () {
+    test('uses the current app name and extension-based workflow', () {
+      for (final locale in AppLocalizations.supportedLocales) {
+        final strings = lookupAppLocalizations(locale);
+        final setupTagline = strings.setupDownloadInFlac.toLowerCase();
+        final firstTip = strings.tutorialWelcomeTip1.toLowerCase();
+
+        expect(
+          strings.tutorialWelcomeTitle,
+          contains('SpotiFLAC Mobile'),
+          reason: 'Unexpected app name for $locale',
+        );
+        expect(
+          setupTagline,
+          isNot(contains('spotify')),
+          reason: 'Provider-specific setup tagline for $locale',
+        );
+        expect(
+          firstTip,
+          isNot(anyOf(contains('spotify'), contains('deezer'))),
+          reason: 'Provider-specific tutorial tip for $locale',
+        );
+      }
+    });
+
+    test('English and Indonesian describe the current feature set', () {
+      final english = lookupAppLocalizations(const Locale('en'));
+      final indonesian = lookupAppLocalizations(const Locale('id'));
+
+      expect(english.tutorialWelcomeDesc, contains('extensions'));
+      expect(english.tutorialLibraryTip2, contains('built-in player'));
+      expect(indonesian.tutorialWelcomeDesc, contains('extension'));
+      expect(indonesian.tutorialLibraryTip2, contains('pemutar bawaan'));
+    });
+  });
+}