feat(admin): Add theme-settings component for global configurations

- Add Schemas/theme-settings.json with analytics and custom_code groups
- Add ThemeSettingsFormBuilder for Admin Panel UI
- Add ThemeSettingsFieldMapper for AJAX field mapping
- Add ThemeSettingsRenderer for injecting GA/CSS/JS
- Add ThemeSettingsInjector for wp_head/wp_footer hooks
- Register component in AdminDashboardRenderer::getComponents()
- Register FieldMapper in FieldMapperProvider

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Admin/Shared/Infrastructure/FieldMapping/FieldMapperProvider.php

@@ -31,6 +31,7 @@ final class FieldMapperProvider
         'RelatedPost',
         'ContactForm',
         'Footer',
+        'ThemeSettings',
     ];
 
     public function __construct(