feat(network): add NetworkClient for TCP communication

- Introduced `NetworkClient` class for client-side TCP communication.
- Implemented `connect`, `send`, and `read` methods for message handling.
- Updated `CMakeLists.txt` to include `NetworkClient.cpp` in the build configuration.

CMakeLists.txt

@@ -16,6 +16,7 @@ add_library(uno-game-lib
         src/network/Message.cpp
         src/network/MessageSerializer.cpp
         src/network/NetworkServer.cpp
+        src/network/NetworkClient.cpp
 )
 target_link_libraries(uno-game-lib
         PRIVATE ftxui::screen

src/network/NetworkClient.cpp

@@ -0,0 +1,39 @@
+/**
+ * @file NetworkClient.cpp
+ *
+ * @author Yuzhe Guo
+ * @date 2025.11.28
+ */
+#include "NetworkClient.h"
+
+#include <asio/connect.hpp>
+#include <asio/read.hpp>
+#include <asio/write.hpp>
+#include <utility>
+
+namespace UNO::NETWORK {
+    NetworkClient::NetworkClient(std::function<void(std::string)> callback) : socket_(io_context_), callback_(std::move(callback)) {}
+
+    void NetworkClient::connect(const std::string &host, uint16_t port)
+    {
+        asio::ip::tcp::resolver resolver(io_context_);
+        auto endpoints = resolver.resolve(host, std::to_string(port));
+        asio::connect(socket_, endpoints.begin(), endpoints.end());
+    }
+
+    void NetworkClient::send(const std::string &message)
+    {
+        size_t length = message.size();
+        asio::write(this->socket_, asio::buffer(&length, sizeof(length)));
+        asio::write(this->socket_, asio::buffer(message));
+    }
+
+    std::string NetworkClient::read()
+    {
+        size_t length;
+        asio::read(this->socket_, asio::buffer(&length, sizeof(length)));
+        std::vector<char> buffer(length);
+        asio::read(this->socket_, asio::buffer(buffer));
+        return {buffer.begin(), buffer.end()};
+    }
+}   // namespace UNO::NETWORK

src/network/NetworkClient.h

@@ -0,0 +1,39 @@
+/**
+ * @file NetworkClient.h
+ *
+ * @author Yuzhe Guo
+ * @date 2025.11.28
+ */
+#pragma once
+#include <asio/io_context.hpp>
+#include <asio/ip/tcp.hpp>
+
+namespace UNO::NETWORK {
+
+    class NetworkClient {
+    private:
+        asio::io_context io_context_;
+        asio::ip::tcp::socket socket_;
+        std::function<void(std::string)> callback_;
+
+    public:
+        explicit NetworkClient(std::function<void(std::string)> callback);
+
+        /**
+         * 连接到服务端
+         * @param host 服务端地址
+         * @param port 服务端端口
+         */
+        void connect(const std::string &host, uint16_t port);
+
+        /**
+         * 向服务端发送消息
+         * @param message 要发送的消息
+         */
+        void send(const std::string &message);
+
+        [[nodiscard]] std::string read();
+    };
+
+}   // namespace UNO::NETWORK
+