refactor: delegate MKMini Gazebo to simulator

src/vehicle_pkg/launch/vehicle.launch.py

@@ -91,7 +91,9 @@ def build(context, *args, **kwargs):
     sim = (sim_mode == 'true')
     actions = []
 
-    # (a) spawn: CARLA only. Gazebo simulator owns the TurtleBot3 entity.
+    # (a) CARLA is still owned by this module. Gazebo is owned by the
+    # dedicated NAV2-Gazebo module so both vehicle profiles use the same
+    # simulation boundary. Real-vehicle paths remain unchanged.
     if sim and plan['simulator'] == 'carla':
         spawn_launch = os.path.join(pkg_share, 'launch', 'carla_spawn_hero.launch.py')
         actions.append(IncludeLaunchDescription(
@@ -107,12 +109,6 @@ def build(context, *args, **kwargs):
                 ('spawn_imu', spawn_imu),
             ],
         ))
-    elif sim and plan['simulator'] == 'gazebo':
-        gazebo_launch = os.path.join(pkg_share, 'launch', 'mkmini_gazebo.launch.py')
-        actions.append(IncludeLaunchDescription(
-            PythonLaunchDescriptionSource(gazebo_launch),
-            launch_arguments=[('gui', gui)],
-        ))
     elif not sim:
         actions.append(Node(package='vehicle_pkg', executable='pub_clock',
                             name='pub_clock', output='screen'))