refactor(custom_robot): Disable LowController functionality temporarily

- Commented out all references to LowController in custom_robot.hpp and custom_robot.cpp to disable its functionality.
- Added warning log in processLowCmd to indicate that LowController functionality is currently disabled until re-implementation.

include/custom_robot.hpp

@@ -5,7 +5,7 @@
 #include "logger.hpp"
 #include "mqtt.hpp"
 #include "navigation.hpp"
-#include "low_controller.hpp"
+// #include "low_controller.hpp"
 
 #include <memory>
 #include <atomic>
@@ -47,7 +47,7 @@ public:
 private:
     std::string generateRandomClientId() const;
     std::unique_ptr<Controller> controller_;
-    std::unique_ptr<LowController> low_controller_;
+    // std::unique_ptr<LowController> low_controller_;
     std::unique_ptr<Navigation> navigation_;
     std::unique_ptr<unitree::robot::go2::RobotStateClient> rsc_;
     std::unique_ptr<MqttClient> mqttClient_;