feat: Divi tools edit Theme Builder layouts; visible layouts need confirm

TB layouts load through ThemeBuilderAccess (P12), live layouts (attached +
enabled, Q8) need a dry run and confirm (Q9) and get the shared restore point
of VisibleEdits, extracted from GlobalEdits (Q2: backup when revisions are
off, P9 refusals, P14 naming). divi/post-content only in body layouts (F22),
also for nested stored nodes. SaveScope::ThemeBuilderLayout sets Divi flags
and clears site CSS + TB cache.

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

tests/Integration/divi-metadata-fixture.php

@@ -18,7 +18,7 @@ if (! class_exists(ModuleRegistration::class)) {
 
 $wanted = [
     'section', 'row', 'column', 'text', 'heading', 'button', 'image', 'blurb', 'code', 'accordion',
-    'accordion-item', 'fullwidth-header', 'group', 'contact-form', 'contact-field',
+    'accordion-item', 'fullwidth-header', 'group', 'contact-form', 'contact-field', 'post-content',
 ];
 $all = ModuleRegistration::get_all_core_modules_metadata();
 $metadata = [];
@@ -40,6 +40,7 @@ foreach ($wanted as $key) {
         'category' => $module['category'] ?? '',
         'childrenName' => $module['childrenName'] ?? null,
         'childModuleName' => $module['childModuleName'] ?? null,
+        'appearance' => $module['appearance'] ?? null,
         'attributes' => $attributes,
     ], static fn ($value): bool => $value !== null);
     $defaults[$module['name']] = ModuleRegistration::get_default_attrs($module['name'], 'default');