[Fix] Cherry-pick docker install extension-startup fix (prebundle deletion, pin-pink)

[hujc7]

Description

Cherry-pick of #6329 onto release/3.0.0-beta2 — the follow-up to #6295 for NVBug 6410989 (continuation of NVBug 6343978): Docker streaming works but the log floods with 438 [Error] lines and 14 Isaac Sim extensions fail to load. uv installs are unaffected.

1. Summary

• Relaxed the vestigial packaging<24 bound in isaaclab_rl — it forced pip to downgrade packaging and delete it from the omni.isaac.core_archive prebundle, dangling the per-file symlink farm omni.services.pip_archive shares with it (13 extension startup failures).
• Bumped pin-pink 3.1.0 → 3.3.0 at every pin site — isaacsim.robot_motion.pink needs pink.exceptions.NoSolutionFound (pink ≥ 3.3.0); pink 3.4+ stays excluded (pink_ik task-API break, Fix pink ik dep pinning #5846). The wheel spec's pin-pink>=2.3.6 also becomes ==3.3.0 (it currently resolves to 4.x).
• Added the fail-loud post-install invariant: the install aborts when pip leaves a prebundled Isaac Sim package with a dangling __init__.py; other new dangling links only warn.

2. Backport adaptations vs #6329

This branch predates the #6009 dependency centralization, so:

• Pin edits land in source/isaaclab/setup.py, source/isaaclab_rl/setup.py, and tools/wheel_builder/res/python_packages.toml instead of the root pyproject.toml.
• The install CLI keeps its hardcoded _PINK_IK_STACK (bumped to 3.3.0); the pyproject-derived stack from [Fix] Stop docker installs breaking Isaac Sim extension startup (prebundle deletion, pin-pink) #6329 and its tests are not ported — the derivation would KeyError here since the root pyproject.toml has no pin entries on this branch.
• import pytest added to test_install_prebundle.py (develop had it from an intermediate commit not on this branch).

3. Heads-up: the invariant can surface latent arm64 breakage

On develop, the first nightly image build containing #6329 failed its arm64 leg because the invariant caught a real prebundle breakage (Pillow deleted from omni.kit.pip_archive). If this release branch's arm64 docker build has a similar latent issue, the invariant will turn a silently-broken image into a failed build — that is by design, but worth knowing before merging.

4. Test plan

• source/isaaclab/test/cli/ — 141 passed locally (prebundle invariant tests included).
• PR CI green.

[greptile-apps]

Greptile Summary

This PR fixes Docker install dependency handling for Isaac Sim prebundles and Pink IK. The main changes are:

• Bumps Pink IK install pins to pin-pink==3.3.0.
• Relaxes the packaging dependency bound in IsaacLab RL and wheel metadata.
• Adds a post-install check for new dangling Isaac Sim prebundle symlinks.
• Adds tests for the new prebundle integrity check.

Confidence Score: 4/5

The changed install path needs a fix for existing incompatible Pink installs.

• The new stack pin installs pin-pink==3.3.0 only when the dependency probe fails.
• An environment with Pink 3.4 or newer can pass that probe and keep the incompatible API.
• The prebundle integrity check matches the intended Docker install failure mode.

source/isaaclab/isaaclab/cli/commands/install.py

Important Files Changed

Filename	Overview
source/isaaclab/isaaclab/cli/commands/install.py	Updates the Pink IK install stack and adds the new prebundle dangling-symlink snapshot/assert flow.
source/isaaclab/test/cli/test_install_prebundle.py	Adds coverage for intact symlink farms, deleted shared package targets, preexisting dangling links, and warning-only dangling files.
source/isaaclab/setup.py	Updates the platform-marked Pink IK dependency pin to pin-pink==3.3.0.
source/isaaclab_rl/setup.py	Relaxes the packaging requirement so pip no longer downgrades the prebundled copy.
tools/wheel_builder/res/python_packages.toml	Mirrors the Pink IK and packaging dependency updates in wheel metadata.
source/isaaclab/isaaclab/controllers/pink_ik/pink_ik.py	Updates Pink IK error messages to recommend the new manual install stack.

_{Reviews (1): Last reviewed commit: "Cherry-pick #6329 docker install fixes t..." | Re-trigger Greptile}

[greptile-apps]

Existing Pink Version Survives

When an environment already has pin-pink 3.4 or newer, the install probe can still pass because it only checks pinocchio, daqp, and qpsolvers. In that state ./isaaclab.sh -i skips the force reinstall, leaves the incompatible Pink API in place, and the Pink IK controller can still fail at runtime even though this stack pin is meant to keep installs on 3.3.0.