Add debug logging for planner mode/speed output

Shows the actual locomotion mode and speed value being sent to the
planner when the stick is active (not IDLE). Helps diagnose whether
SLOW_WALK mode is being selected and speeds are in-distribution.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gear_sonic_deploy/src/g1/g1_deploy_onnx_ref/include/input_interface/gamepad_manager.hpp

@@ -726,6 +726,12 @@ class GamepadManager : public InputInterface {
         }
 
         MovementState mode_state(final_mode, final_movement, final_facing_direction, final_speed, final_height);
+        if constexpr (DEBUG_LOGGING) {
+          if (final_mode != static_cast<int>(LocomotionMode::IDLE)) {
+            std::cout << "[GamepadManager] -> Planner: mode=" << final_mode
+                      << " speed=" << final_speed << " mag=" << planner_stick_magnitude_ << std::endl;
+          }
+        }
         movement_state_buffer.SetData(mode_state);
       }
     }