fix: record json_coding step and forward serialNumber in JsonCodingHandler

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/Infrastructure/Messenger/Handler/JsonCodingHandler.php

@@ -41,11 +41,15 @@ final class JsonCodingHandler
 
         $attributes = $this->jsonAgent->encode($articleType, $message->specsText, $message->missingFields);
 
+        $job->recordStep('json_coding', ['attributes' => $attributes]);
+        $this->jobRepository->save($job);
+
         $this->bus->dispatch(new ValidationMessage(
             jobId: $message->jobId,
             articleTypeId: $message->articleTypeId,
             specsText: $message->specsText,
             attributes: $attributes,
+            serialNumber: $message->serialNumber,
         ));
     }
 }