feat: explain the type collision on contact fields (trial)

A contact-field item whose type is no allowed child now gets a hint that
type is the node type, with the attrs path (fieldItem.advanced.type) and
the lit-divi-update set alternative, instead of "unbekanntes Modul
divi/email". The metadata fixture gains contact-form/contact-field
(regenerated from Divi 5.2.1, additions only).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

tests/Unit/Integrations/Divi/Compose/ComposerTest.php

@@ -530,4 +530,26 @@ final class ComposerTest extends TestCase
 
         self::assertStringContainsString('2 Spalten, aber 3 Modul-Listen', $result['errors']['nodes[0].rows[0].modules']);
     }
+
+    /**
+     * Trial feedback: `type` on a contact field is the node type, not the field type. A value that
+     * is no allowed child gets a dedicated hint instead of "unbekanntes Modul divi/email".
+     */
+    public function testTypeOnAnItemWithATypeFieldExplainsTheCollision(): void
+    {
+        $result = ComposeFixture::composer()->compose([['type' => 'section', 'modules' => [
+            ['type' => 'contact-form', 'items' => [
+                ['title' => 'Name'],
+                ['type' => 'email', 'title' => 'E-Mail'],
+                ['type' => 'contact-field', 'title' => 'Nachricht'],
+            ]],
+        ]]], null, 'nodes');
+
+        $message = $result['errors']['nodes[0].modules[0].modules[0][0].items[1].type'] ?? '';
+        self::assertStringContainsString('`type` ist hier der Knotentyp', $message);
+        self::assertStringContainsString('fieldItem.advanced.type', $message);
+        self::assertStringContainsString('"email"', $message);
+        self::assertStringNotContainsString('unbekanntes Modul', $message);
+        self::assertCount(1, $result['errors'], 'the explicit contact-field type is fine');
+    }
 }