feat: {{link:ID}} placeholder via Divi's post_link_url dynamic content

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

tests/Unit/Integrations/Divi/Pages/DiviCompositionTest.php

@@ -37,7 +37,14 @@ final class DiviCompositionTest extends TestCase
             return DiviFixtures::dynamicContentRegistry();
         });
 
-        return new DiviComposition($modules, $design, ComposeFixture::sanitizer(), ComposeFixture::media(), $registry);
+        return new DiviComposition(
+            $modules,
+            $design,
+            ComposeFixture::sanitizer(),
+            ComposeFixture::media(),
+            $registry,
+            ComposeFixture::links()
+        );
     }
 
     private static function siteTitle(): string
@@ -74,6 +81,24 @@ final class DiviCompositionTest extends TestCase
         self::assertSame($composition->references(), $composition->references());
     }
 
+    /** E13a: the composition hands its link targets to Placeholders; the result still passes ValueCleaner. */
+    public function testInternalLinksUseTheLinkTargets(): void
+    {
+        $composer = $this->composition()->forPost(7)->composer();
+
+        $column = Block::create('divi/column');
+
+        $page = $composer->compose([['type' => 'button', 'text' => 'Kontakt', 'url' => '{{link:839}}']], $column, 'nodes');
+        self::assertSame([], $page['errors']);
+        self::assertStringContainsString(
+            'post_link_url_page',
+            json_encode($page['blocks'][0]->attrs(), JSON_THROW_ON_ERROR)
+        );
+
+        $missing = $composer->compose([['type' => 'button', 'url' => '{{link:999}}']], $column, 'nodes');
+        self::assertStringContainsString('Eintrag 999', $missing['errors']['nodes[0].url']);
+    }
+
     public function testWithoutAPostTheDefaultMapApplies(): void
     {
         $composition = $this->composition();