feat: lit-divi-insert prüft Schleifen-Inhalte im Kontext des Ziels; neue Schleife plus Inhalt in einem Aufruf fail closed (X3)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Integrations/Divi/Pages/DiviWriteAbility.php

@@ -6,6 +6,10 @@ namespace LIT\MCP\Integrations\Divi\Pages;
 
 use LIT\MCP\Abilities\Ability;
 use LIT\MCP\Abilities\ToolResult;
+use LIT\MCP\Integrations\Divi\BlockTree\Block;
+use LIT\MCP\Integrations\Divi\BlockTree\NodeIndex;
+use LIT\MCP\Integrations\Divi\Compose\LoopContext;
+use LIT\MCP\Integrations\Divi\Compose\LoopScope;
 use LIT\MCP\Integrations\Divi\Release\DiviFeature;
 use LIT\MCP\Integrations\Divi\Release\FeatureSets;
 use LIT\MCP\Integrations\Divi\Release\RequiresDiviFeatures;
@@ -114,4 +118,22 @@ abstract class DiviWriteAbility implements Ability, RequiresDiviFeatures
     {
         return null;
     }
+
+    /**
+     * Ruling X3: the loop scope at $block – its nearest loop-enabled ancestor-or-self (LoopContext, X1); none at
+     * the top level. $newAttrs (node ID => attrs) replaces the stored attrs of nodes this call changes. The index
+     * is the tree loaded for this call, never a client value. Opaque blocks are never entered by NodeIndex, so one
+     * can only be $block itself – and every tool refuses to write into or onto it.
+     *
+     * @param array<string, array<string, mixed>> $newAttrs
+     */
+    protected static function loopAt(NodeIndex $index, ?Block $block, array $newAttrs = []): LoopScope
+    {
+        $chain = [];
+        for ($node = $block; $node !== null; $node = $index->parentBlock($node)) {
+            array_unshift($chain, $newAttrs[(string) $index->idOf($node)] ?? $node->attrs());
+        }
+
+        return LoopContext::fromChain($chain);
+    }
 }