refactor(settings): Use specific l10n keys for titles

Author: fulleni

lib/settings/view/appearance_settings_page.dart

@@ -34,7 +34,7 @@ class AppearanceSettingsPage extends StatelessWidget {
         children: [
           ListTile(
             leading: const Icon(Icons.color_lens_outlined),
-            title: Text(l10n.settingsAppearanceTitle), // Placeholder: "Appearance Settings"
+            title: Text(l10n.settingsAppearanceThemeSubPageTitle), // Use new l10n key
             trailing: const Icon(Icons.chevron_right),
             onTap: () {
               context.goNamed(Routes.settingsAppearanceThemeName);
@@ -43,7 +43,7 @@ class AppearanceSettingsPage extends StatelessWidget {
           const Divider(indent: AppSpacing.lg, endIndent: AppSpacing.lg),
           ListTile(
             leading: const Icon(Icons.font_download_outlined),
-            title: Text(l10n.settingsAppearanceTitle), // Placeholder: "Appearance Settings"
+            title: Text(l10n.settingsAppearanceFontSubPageTitle), // Use new l10n key
             trailing: const Icon(Icons.chevron_right),
             onTap: () {
               context.goNamed(Routes.settingsAppearanceFontName);