Refactor logoExists function to resolve absolute file paths relative to index.php

index.php

@@ -60,7 +60,8 @@ $projects = [
  * Verhindert Broken Images.
  */
 function logoExists(string $webPath): bool {
-    $filePath = $_SERVER['DOCUMENT_ROOT'] . $webPath;
+    // Absoluten Dateisystempfad relativ zur index.php auflösen
+    $filePath = __DIR__ . '/' . ltrim($webPath, '/');
     return is_file($filePath);
 }