refactor(navigation): 重构Navigation类继承unitree::robot::Client

移除不必要的client_成员变量，直接继承unitree::robot::Client类
简化初始化逻辑，更新相关文档说明

include/navigation.hpp

@@ -8,7 +8,7 @@
 
 namespace custom {
 
-class Navigation {
+class Navigation : public unitree::robot::Client {
 public:
     Navigation();
     ~Navigation();
@@ -24,7 +24,6 @@ public:
     bool closeSlam();
 
 private:
-    std::unique_ptr<unitree::robot::Client> client_;
     bool callSlamService(int api_id, const nlohmann::json& data);
 };