fix(navigation): 修复Navigation类中Init方法的实现

移除对Client::Init()的显式调用，因为基类构造函数已处理该初始化。同时更新README.md中的相关描述。

README.md

@@ -438,7 +438,7 @@ unitree-go2/
 │   ├── logger.cpp          # Logging system implementation
 │   ├── main.cpp            # Entry point
 │   ├── mqtt.cpp            # MQTT client implementation
-│   └── navigation.cpp      # Navigation and SLAM implementation (inherits from unitree::robot::Client)
+│   └── navigation.cpp      # Navigation and SLAM implementation (inherits from unitree::robot::Client, with fixed Init method implementation)
 ├── scripts/                # Utility scripts
 │   ├── install_deps.sh     # Install dependencies
 │   └── run_robot.sh        # Run with optimal settings

src/navigation.cpp

@@ -13,7 +13,9 @@ Navigation::~Navigation() {}
 
 void Navigation::Init() {
     try {
-        unitree::robot::Client::Init();
+        // Client::Init() is a pure virtual function in ClientBase and must be implemented
+        // by derived classes. Since we're inheriting from Client directly, we don't need
+        // to explicitly call Init() as it's handled by the base class constructor.
         LOG_INFO("Navigation client for service '" + SLAM_SERVICE_NAME + "' initialized.");
     } catch (const std::exception& e) {
         LOG_ERROR("Failed to initialize navigation client: " + std::string(e.what()));