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/ThemeSettings/Infrastructure/FieldMapping/ThemeSettingsFieldMapper.php

@@ -0,0 +1,37 @@
+<?php
+declare(strict_types=1);
+
+namespace ROITheme\Admin\ThemeSettings\Infrastructure\FieldMapping;
+
+use ROITheme\Admin\Shared\Domain\Contracts\FieldMapperInterface;
+
+/**
+ * Field Mapper para Theme Settings
+ *
+ * RESPONSABILIDAD:
+ * - Mapear field IDs del formulario a atributos de BD
+ * - Solo conoce sus propios campos (modularidad)
+ *
+ * NOTA: Logo/branding se gestiona desde el componente navbar
+ */
+final class ThemeSettingsFieldMapper implements FieldMapperInterface
+{
+    public function getComponentName(): string
+    {
+        return 'theme-settings';
+    }
+
+    public function getFieldMapping(): array
+    {
+        return [
+            // Analytics
+            'themeSettingsGaTrackingId' => ['group' => 'analytics', 'attribute' => 'ga_tracking_id'],
+            'themeSettingsGaAnonymizeIp' => ['group' => 'analytics', 'attribute' => 'ga_anonymize_ip'],
+
+            // Custom Code
+            'themeSettingsCustomCss' => ['group' => 'custom_code', 'attribute' => 'custom_css'],
+            'themeSettingsCustomJsHeader' => ['group' => 'custom_code', 'attribute' => 'custom_js_header'],
+            'themeSettingsCustomJsFooter' => ['group' => 'custom_code', 'attribute' => 'custom_js_footer'],
+        ];
+    }
+}