feat(theme-settings): agregar configuracion de ancho del contenedor

- Nuevo grupo 'Layout y Contenedor' en theme-settings
- Opciones: 1140px, 1200px, 1320px (default), 1400px, 100%
- CSS dinamico aplicado via ThemeSettingsRenderer
- Corregir selectores de hero en Rail Ads (.hero-section, .featured-image-container)
- Agregar setTimeout para esperar carga de DOM
- Aumentar gap de separacion a 30px
- Subir maxTop al 40% del viewport

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

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

Admin/ThemeSettings/Infrastructure/FieldMapping/ThemeSettingsFieldMapper.php

@@ -24,6 +24,10 @@ final class ThemeSettingsFieldMapper implements FieldMapperInterface
     public function getFieldMapping(): array
     {
         return [
+            // Layout
+            'themeSettingsContainerMaxWidth' => ['group' => 'layout', 'attribute' => 'container_max_width'],
+            'themeSettingsContentColumnWidth' => ['group' => 'layout', 'attribute' => 'content_column_width'],
+
             // Custom Code
             'themeSettingsCustomCss' => ['group' => 'custom_code', 'attribute' => 'custom_css'],
             'themeSettingsCustomJsHeader' => ['group' => 'custom_code', 'attribute' => 'custom_js_header'],