Make XR experiences show all scene partitions

[hougantc-nvda]

Description

Default-on per-environment Isaac RTX scene partitioning requires an unpartitioned spectator view for XR. This PR sets:

rtx.scenePartitioning.showAllPartitionsByDefault = true

in exactly the two standard OpenXR experiences, before RTX startup:

• apps/isaaclab.python.xr.openxr.kit
• apps/isaaclab.python.xr.openxr.headless.kit

It also adds a focused static contract test for both experience files and a changelog fragment. No dependencies are added.

Baseline interpretation

Current develop already injects --/rtx/scenePartitioning/showAllPartitionsByDefault=true from AppLauncher whenever XR is requested (merged in #7053). Therefore the normal uv run --extra teleop ... --xr path is expected to be configured correctly before this PR.

This change does not claim to introduce the Isaac Sim 6.1 renderer fix or to make an already-failing AppLauncher path pass. It makes the shipped XR experience files self-contained and safe when launched directly or through a path that does not use AppLauncher.

Type of change

• Bug fix (non-breaking configuration fix)
• New feature
• Breaking change
• Documentation update

Validation

Controlled static before/after

• Before, with the regression assertion added but both experience files unmodified: 2 failed, 6 passed; both XR cases failed because the setting was absent.
• After adding the two settings: 8 passed.
• Final focused suite, including current AppLauncher XR argument coverage: 23 passed.
• pre-commit run --all-files: all hooks passed, including TOML, RST, changelog, spelling, formatting, and Git LFS pointer checks.
• IsaacLab reviewer risk scan and manual sibling-entry-point audit: no findings at 397685bada014f4911a4f3f05b80d4e464cb0b7c.

Isaac Sim / Kit target and runtime limitation

The develop CI pin is:

• Isaac Sim 6.1.0-alpha.50 (b86cf6ce)
• Kit 110.3.0-360924
• Image digest sha256:e7cd73cd7a9a6621274bd3a1bacddfd4ac1a15f92893e6a10cfb6b8100762a0c

The exact image is on Isaac Lab's internal NGC mirror. The local Horde account was denied access to that manifest, and the only locally installed Kit oracle is Isaac Sim 6.0.1.0, which does not contain /rtx/scenePartitioning/showAllPartitionsByDefault. I did not substitute 6.0.1 for the required 6.1 validation.

Consequently, this draft does not claim that the requested runtime command was exercised on 6.1, nor that the steering wheel, bin/environment geometry, or robot PiP were visually verified in IWER. The upstream PR workflow is configured to build and test against the exact pinned 6.1 image; visual IWER validation remains outstanding.

Screenshots

Not available because the exact 6.1 XR/IWER runtime could not be launched from the local Horde account.

Checklist

• I have read and understood the contribution guidelines.
• I have run the all-files pre-commit checks.
• No public API documentation change is required; the user-visible fix has a changelog fragment.
• The static and focused tests generate no new warnings.
• I have added a focused test that proves both shipped XR experiences carry the startup setting.
• I have added an isaaclab changelog fragment.
• Hougant Chen is already listed in CONTRIBUTORS.md.