Remove packing_area_warehouse background (superseded by packing_area_simple)

Fix packing_area_simple: shell at identity (rack no longer behind dividing wall), tuned lighting (fill 2000, dome 60, no key) (part 2)

Fix packing_area_simple: shell at identity (rack no longer behind dividing wall), tuned lighting (fill 2000, dome 60, no key)

Add packing_area_simple background (Isaac Simple_Warehouse shell + same packing-area furniture) (part 2)

Add packing_area_simple background (Isaac Simple_Warehouse shell + same packing-area furniture)

Prune 425 distant warehouse light fixtures (render perf); keep 128 near the packing area

Rebuild background in benchmark frame: origin at table, x long axis, rack/wall behind robot

Add packing_area_warehouse background (self-contained USD scene)