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>

src/Plugin.php

@@ -24,6 +24,7 @@ use LIT\MCP\Guides\InstructionsBuilder;
 use LIT\MCP\Integrations\Core\CoreIntegration;
 use LIT\MCP\Integrations\Divi\DiviIntegration;
 use LIT\MCP\Integrations\Divi\Library\LibraryAccess;
+use LIT\MCP\Integrations\Divi\ThemeBuilder\ThemeBuilderAccess;
 use LIT\MCP\Integrations\IntegrationRegistry;
 use LIT\MCP\Integrations\Media\MediaIntegration;
 use LIT\MCP\Integrations\Pods\PodsFieldSource;
@@ -95,13 +96,22 @@ final class Plugin
                 && $policy instanceof ExposurePolicy
                 && $policy->allows('lit/library-insert', $registry->abilities());
         };
+        // Etappe 3b: the group "Divi Theme Builder" gates TB layouts in the Divi tools like the library group (E9).
+        $themeBuilderVisible = static function () use (&$policy): bool {
+            return $policy instanceof ExposurePolicy && $policy->groupEnabled(ThemeBuilderAccess::GROUP);
+        };
+        $themeBuilderWritable = static function () use (&$policy): bool {
+            return $policy instanceof ExposurePolicy && $policy->groupWritable(ThemeBuilderAccess::GROUP);
+        };
         $divi = new DiviIntegration(
             $schema,
             $changeLog,
             $libraryWritable,
             libraryVisible: $libraryVisible,
             diviWritable: $diviWritable,
-            libraryInsertable: $libraryInsertable
+            libraryInsertable: $libraryInsertable,
+            themeBuilderWritable: $themeBuilderWritable,
+            themeBuilderVisible: $themeBuilderVisible
         );
         $registry = new IntegrationRegistry(
             new CoreIntegration(self::pluginDir() . '/docs/guides'),