- Add NodeConfig: simplified INI config manager for embedded uTun node
- X25519 key generation via OpenSSL EVP
- Random node_id generation
- addServer/removeServer, addClient/removeClient API
- Auto-creates config with default server on first run
- Integrate UtunNode into MainWindow:
- Creates NodeConfig in ~/.config/chatgui/node.conf
- Starts embedded uTun node (no TUN, no msg_transport)
- In separate thread with uasync_poll event loop
- Replace MsgClient (TCP IPC) with UtunNode (direct calls):
- ChatPropagator now uses UtunNode for send/recv
- send(uint64_t, QByteArray) replaces sendTo
- messageReceived signal replaces received signal
- MainWindow cleanup: remove MsgClient, add UtunNode+NodeConfig