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/Integrations/Divi/Pages/DiviComposition.php

@@ -36,6 +36,7 @@ defined('ABSPATH') || exit;
 class DiviComposition
 {
     private ?int $postId = null;
+    private ?string $themeBuilderArea = null;
     private ?VariableRef $references = null;
     private ?Placeholders $placeholders = null;
     private ?ValueCleaner $cleaner = null;
@@ -52,11 +53,12 @@ class DiviComposition
     ) {
     }
 
-    /** A fresh composition for entry $postId (own VariableRef with that entry's live map). */
-    public function forPost(int $postId): static
+    /** A fresh composition for entry $postId (own VariableRef with its live map; TB area for StructureRules). */
+    public function forPost(int $postId, ?string $themeBuilderArea = null): static
     {
         $bound = clone $this;
         $bound->postId = $postId;
+        $bound->themeBuilderArea = $themeBuilderArea;
         $bound->references = null;
         $bound->placeholders = null;
         $bound->cleaner = null;
@@ -116,7 +118,7 @@ class DiviComposition
     /** @internal Public for tests; code uses composer() / editor(). */
     public function rules(): StructureRules
     {
-        return new StructureRules($this->modules->catalog());
+        return new StructureRules($this->modules->catalog(), $this->themeBuilderArea);
     }
 
     /** E6: the check for stored nodes that move into this composition's entry (same cleaner and references). */