refactor: Divi pages adapter replaces DiviFlags

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/Integrations/WordPress/Content/PostPresenter.php

@@ -6,6 +6,7 @@ namespace LIT\MCP\Integrations\WordPress\Content;
 
 use LIT\MCP\Abilities\JsonMap;
 use LIT\MCP\Abilities\Rev;
+use LIT\MCP\Integrations\Divi\Pages\DiviPages;
 use LIT\MCP\Integrations\Divi\Schema\DiviModules;
 use LIT\MCP\Integrations\WordPress\Schema\ContentSchema;
 use LIT\MCP\Integrations\WordPress\Schema\FieldDefinition;
@@ -95,7 +96,7 @@ class PostPresenter
 
     public static function usesDivi(WP_Post $post): bool
     {
-        return get_post_meta((int) $post->ID, '_et_pb_use_builder', true) === 'on'
+        return DiviPages::usesBuilder((int) $post->ID)
             || str_contains((string) $post->post_content, '<!-- wp:divi/');
     }