[maxkra15]

Description

Adds IsaacContrib-Conveyor-Warehouse-Sorting-v0: a 24-parcel pool uses four policy slots and class metadata to route four colors onto two circulating conveyors. Reuses the racetrack observations/actions and an authored USD warehouse.

A standard hidden ground plane replaces the custom terrain importer. Physics stays in the policy workspace; presentation roots and camera share one translation. This also fixes a persistent reset bug that applied the warehouse height twice to the robot. Asset spawning uses stock mesh/cuboid APIs, visual physics stripping has one pass, and arrivals use batched goal assignment.

NVIDIA geometry and textures remain remote references under their original licenses. Depends on #8331/#8327. Review warehouse changes. PhysX is independent and optional (#8794).

Validation and limitation

• 13 combined task/geometry and four asset/animation cases passed, including mounted-base resets, dispatch, inventory, selected resets and the active Kit camera.
• 70 bodies, 219 native shapes and 111 authored source bounds preserve normalized geometry, materials and camera alignment after correcting the old reset defect.
• The mounted-base keeper fails the old duplicate height; the simultaneous-arrival keeper rejects cross-environment slot broadcasts.
• Full formatting/lint/changelog/LFS, browser and lock checks passed; strict combined documentation build passed.

Warehouse policy success is not established. With model_1100.pt, seed 41, two environments and 2,400 steps, both the historical scene with corrected robot height and the simplified scene completed zero transfers, with zero failures/non-finite observations. Arrivals and targets were active. This PR remains a draft; these checks establish scene/dispatch contracts, not successful batch sorting.

Checklist

• Followed contribution and test-audit guidance.
• Ran focused tests and repository formatting/lint checks.
• Updated documentation and package changelog.
• Contributor already listed in CONTRIBUTORS.md.