Add lab desk objects to MuJoCo scene

[davetcoleman]

Summary

• Replace blocks on lab desk with realistic lab environment objects built from MuJoCo primitives
• New objects: desk lamp, laptop (with MoveIt Pro behavior tree screenshot as screen texture and keyboard checker texture), fake potted plant, alligator trophy statue on shelf, test tube rack with 6 manipulable colored tubes, and 4 manipulable medicine bottles
• Reposition original test tube stand behind new custom rack
• Add "Crouch down" waypoint to ur_waypoints.yaml

Dependencies

• Requires picknik_accessories#feature/lab-sim-desk-objects for the test tube stand repositioning

Test plan

• Launch lab_sim in MuJoCo and verify all objects render correctly on the desk surface
• Verify test tubes and medicine bottles are manipulable (have freejoints)
• Verify laptop displays the MoveIt Pro screenshot texture on screen
• Verify alligator trophy is positioned on the top shelf
• Confirm no objects are floating or falling through the table

🤖 Generated with Claude Code

[davetcoleman]

@MikeWrock i dont understand why some things live in this picknik_accessories, and others in the example_ws. Can we get rid of picknik_accessories? What's the point? We have GitLFS already.

[MikeWrock]

I'm not sure what things are living in example_ws, but the idea is to have one repo that can hold all our reusable assets, and if you have config specific assets that cannot justifiably be put in the accessories package then it can live in the config package. Due to https://github.com/PickNikRobotics/moveit_pro/issues/13842 we have to do a little CMake hacking so that we can re-use these assets, otherwise they would have to be duplicated within each package that used them and copied out for re-use

[davetcoleman]

But who is reusing these assets? It appears these assets are just used in the example_ws

I propose I have Claude merge these repos together. Maybe @nbbrooks has thoughts.

[davetcoleman]

remove this commented out section