fix(turnero): save outgoing messages with canal='turnero' so they appear in chat

saveOutgoingMessage() now reads __app_meta.canal and stores it in conversations.
sendMediaById() accepts a $meta param and forwards it to saveOutgoingMessage.
chat_upload_media.php passes $extra (canal=turnero) to sendMediaById.

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

modules/turnero/api/chat_upload_media.php

@@ -57,7 +57,8 @@ try {
         $caption ?: null,
         $file['name'],
         false,
-        $isVoice
+        $isVoice,
+        $extra
     );
 
     echo json_encode(['success' => true, 'media_type' => $mediaType, 'response' => $resp]);