refactor: Divi design adapter, logo lookup moves out of media

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

src/Integrations/Media/MediaUsageFinder.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace LIT\MCP\Integrations\Media;
 
 use Closure;
+use LIT\MCP\Integrations\Divi\Design\DesignSystemReader;
 use LIT\MCP\Integrations\WordPress\PostStatuses;
 use LIT\MCP\Log;
 
@@ -256,10 +257,14 @@ class MediaUsageFinder
             );
         }
 
-        $divi = get_option('et_divi');
-        $diviLogo = is_array($divi) && is_string($divi['divi_logo'] ?? null) ? $divi['divi_logo'] : '';
+        $diviLogo = DesignSystemReader::diviLogo();
         if ($diviLogo !== '' && ContentMediaReferences::matches($fileRegex, $diviLogo) !== false) {
-            $found['site:divi_logo'] = self::siteUsage('Divi-Logo', 'option', 'divi_logo', self::POSSIBLE);
+            $found['site:divi_logo'] = self::siteUsage(
+                'Divi-Logo',
+                'option',
+                'divi_logo',
+                self::POSSIBLE
+            );
         }
 
         $this->addWidgetUsages($found, $attachmentId, $fileRegex);