重构网络管理，移除TCPClient和TCPServer类，整合多路复用功能，优化连接管理和数据传输逻辑

net/multiplex_manager.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <unordered_map>
+#include <memory>
+#include <mutex>
+#include <vector>
+#include <string>
+#include <boost/asio.hpp>
+#include <steam_api.h>
+#include <isteamnetworkingsockets.h>
+#include <steamnetworkingtypes.h>
+
+using boost::asio::ip::tcp;
+
+class MultiplexManager {
+public:
+    MultiplexManager(ISteamNetworkingSockets* steamInterface, HSteamNetConnection steamConn, 
+                     boost::asio::io_context& io_context, bool& isHost, int& localPort);
+    ~MultiplexManager();
+
+    std::string addClient(std::shared_ptr<tcp::socket> socket);
+    void removeClient(const std::string& id);
+    std::shared_ptr<tcp::socket> getClient(const std::string& id);
+
+    void sendTunnelPacket(const std::string& id, const char* data, size_t len, int type);
+
+    void handleTunnelPacket(const char* data, size_t len);
+
+private:
+    ISteamNetworkingSockets* steamInterface_;
+    HSteamNetConnection steamConn_;
+    std::unordered_map<std::string, std::shared_ptr<tcp::socket>> clientMap_;
+    std::mutex mapMutex_;
+    boost::asio::io_context& io_context_;
+    bool& isHost_;
+    int& localPort_;
+};