android: voice messages + attachments architecture plan, build fixes

tools/chatgui/transport/node_config.cpp

@@ -1,6 +1,7 @@
 // node_config.cpp — Simplified INI config manager for embedded uTun node
 #include "node_config.h"
 #include "config_updater.h"
+#include <QHostInfo>
 
 extern "C" {
 #include <openssl/evp.h>
@@ -165,7 +166,12 @@ void NodeConfig::generateIdentity() {
 }
 
 bool NodeConfig::create(const QString& nodeName, quint16 listenPort) {
-    m_nodeName = nodeName.isEmpty() ? "chatgui" : nodeName;
+    if (nodeName.isEmpty()) {
+        QString host = QHostInfo::localHostName();
+        m_nodeName = host.isEmpty() ? "chatgui" : host;
+    } else {
+        m_nodeName = nodeName;
+    }
     if (m_pubKey.isEmpty()) generateIdentity();
     if (m_controlAddr.isEmpty())
         m_controlAddr = "127.0.0.1:9999";