feat: lit/library-save creates library entries like Divi (E4)

Reuses NewDraft for insert and rollback (P6), requires edit_global_library
for scope global (P7), refuses opaque and global roots before wrapping (P11)
and checks the node with StoredNodeGuard. The source page is never written.

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

src/Integrations/Divi/Library/LibraryIntegration.php

@@ -4,15 +4,18 @@ declare(strict_types=1);
 
 namespace LIT\MCP\Integrations\Divi\Library;
 
+use LIT\MCP\ChangeLog\ChangeLog;
 use LIT\MCP\Integrations\Divi\Design\DesignSystemReader;
 use LIT\MCP\Integrations\Divi\Pages\DiviPageLoader;
+use LIT\MCP\Integrations\Divi\Pages\DiviSaver;
+use LIT\MCP\Integrations\Divi\Pages\DiviWriter;
 use LIT\MCP\Integrations\Divi\Schema\DiviModules;
 use LIT\MCP\Integrations\Integration;
 
 defined('ABSPATH') || exit;
 
 /**
- * The group "Divi-Bibliothek" (E9): lit/library-list, later lit/library-save and lit-library-insert.
+ * The group "Divi-Bibliothek" (E9): lit/library-list, lit/library-save, later lit-library-insert.
  * Built by DiviIntegration::library() so it shares the library access (rights, Tools-tab gates –
  * its id LibraryAccess::GROUP is what the P9 hiding and the write gate ask). Available with the
  * Divi 5 builder, like the Divi group.
@@ -22,7 +25,11 @@ final class LibraryIntegration implements Integration
     public function __construct(
         private LibraryAccess $access,
         private DiviPageLoader $loader,
-        private DesignSystemReader $design
+        private DesignSystemReader $design,
+        private DiviWriter $writer,
+        private DiviSaver $saver,
+        private ChangeLog $log,
+        private DiviModules $modules
     ) {
     }
 
@@ -45,6 +52,14 @@ final class LibraryIntegration implements Integration
     {
         return [
             new LibraryListAbility($this->access, $this->loader, $this->design, new GlobalUsages()),
+            new LibrarySaveAbility(
+                $this->access,
+                $this->loader,
+                $this->writer,
+                $this->saver,
+                $this->log,
+                $this->modules
+            ),
         ];
     }
 }