Initial commit: FAST-LIO ROS2 workspace for duru_lio

Clean up config/rviz assets for MID360S-only deployment and split
run scripts by role (headless LIO via ssh, rviz-only on the local
monitor, and combined run) so mapping.launch.py no longer needs
config_file passed explicitly.

msg/Pose6D.msg

@@ -0,0 +1,7 @@
+# the preintegrated Lidar states at the time of IMU measurements in a frame
+float64  offset_time # the offset time of IMU measurement w.r.t the first lidar point
+float64[3] acc       # the preintegrated total acceleration (global frame) at the Lidar origin
+float64[3] gyr       # the unbiased angular velocity (body frame) at the Lidar origin
+float64[3] vel       # the preintegrated velocity (global frame) at the Lidar origin
+float64[3] pos       # the preintegrated position (global frame) at the Lidar origin
+float64[9] rot       # the preintegrated rotation (global frame) at the Lidar origin