fix: P8a blocks Theme Builder layouts without Divi's theme_builder role (L6)

et_header_layout, et_body_layout, et_footer_layout and et_template showing a
global entry now block a confirmed edit unless et_pb_is_allowed('theme_builder'),
like Divi's own check for TB layouts.

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

src/Integrations/Divi/Library/DiviRoles.php

@@ -25,6 +25,7 @@ class DiviRoles
         'add_library' => 'Aus der Bibliothek hinzufügen',
         'edit_global_library' => 'Globale Bibliothekselemente bearbeiten',
         'read_dynamic_content_custom_fields' => 'Dynamic Content: benutzerdefinierte Felder lesen',
+        'theme_builder' => 'Theme Builder',
     ];
 
     /** @param (Closure(string): bool)|null $check Test seam; null = Divi's et_pb_is_allowed(). */