fix: voice message JSON double-nesting, '{' display

- req->data now stores 'filename|duration' instead of full nested JSON
- chat_core_submit_message builds the JSON with d='filename|duration'
- setVoiceMessageRoles splits d field by '|' to extract filename and duration

tools/chatgui/src/messagelist.cpp

@@ -94,9 +94,11 @@ static void setVoiceMessageRoles(QStandardItem* item, const QByteArray& data,
     item->setData(ct, MsgContentTypeRole);
 
     if (ct == "audio/opus") {
-        QString dur = parseJsonFieldNum(data, "dur");
+        QString raw = parseJsonField(data, "d");
+        int pipe = raw.indexOf('|');
+        QString fname = pipe >= 0 ? raw.left(pipe) : raw;
+        QString dur = pipe >= 0 ? raw.mid(pipe + 1) : QString();
         if (!dur.isEmpty()) item->setData(dur + "s", MsgVoiceDurationRole);
-        QString fname = parseJsonField(data, "d");
         if (!fname.isEmpty()) {
             QString fullPath = mediaDirBase + "/" + channelId + "/" + fname;
             item->setData(fullPath, MsgVoiceFileRole);
@@ -197,13 +199,8 @@ MessageList::MessageList(DbManager* db, AudioRecorder* recorder, QWidget *parent
 
         QFileInfo fi(filePath);
         QString fileName = fi.fileName();
-        QString jsonData = QString("{\"n\":%1,\"ch\":\"%2\",\"ct\":\"audio/opus\",\"d\":\"%3\",\"dur\":%4}")
+        QByteArray textData = (fileName + "|" +
-            .arg(m_db ? m_db->myNodeId() : 0)
+            QString::number(durationMs / 1000.0, 'f', 1)).toUtf8();
-            .arg(m_currentChannelId)
-            .arg(fileName)
-            .arg(durationMs / 1000.0, 0, 'f', 1);
-
-        QByteArray textData = jsonData.toUtf8();
         auto ts = QDateTime::currentMSecsSinceEpoch();
 
         struct chat_msg_submit* req = (struct chat_msg_submit*)