Merge Cartpole Direct and Manager, Remove deprecated task names

[StafaH]

Description

This PR overhauls the isaaclab_tasks package layout and consolidates the Cartpole
task family. It is primarily a breaking refactor of import paths and registered Gym
environment IDs, with corresponding updates across the docs, example/training scripts,
GitHub Actions workflows, and tests.

The changes fall into three parts:

1. Merged Cartpole packages. The direct-workflow and manager-based-workflow Cartpole
   packages (isaaclab_tasks.core.direct_cartpole and isaaclab_tasks.core.manager_cartpole)
   are merged into a single flat isaaclab_tasks.core.cartpole package. Module files now
   carry a _direct_ or _manager_ infix to disambiguate the two workflows. The Cartpole
   Gym environment IDs were renamed to spell out their workflow and drop the -v0 version
   suffix (e.g. Isaac-Cartpole-Direct-v0 → Isaac-Cartpole-Direct,
   Isaac-Cartpole-v0 → Isaac-Cartpole-Manager).

2. Removed deprecated Cartpole task IDs. Removed 35 per-variant Cartpole task IDs
   (7 Direct camera, 4 manager-based camera, 15 proprioceptive showcase, 9 camera-based
   showcase) along with the deprecated gym.register kwarg that flagged them as aliases.
   These variants are now selected via the consolidated tasks plus presets=<name>
   (e.g. Isaac-Cartpole-{RGB,Depth,...}-Camera-Direct-v0 →
   --task=Isaac-Cartpole-Camera-Direct presets=<rgb|depth|albedo|...>). A handful of other
   stale environments (Isaac-Quadcopter-Direct-v0, Isaac-Lift-Teddy-Bear-Franka-IK-Abs-v0,
   Isaac-Repose-Cube-Allegro-NoVelObs-v0, Isaac-Repose-Cube-Allegro-NoVelObs-Play-v0)
   were also removed.

Docs, RL/example scripts, the multi-GPU GitHub Actions workflow, AGENTS.md, and the
affected test suite were updated to use the new task IDs and import paths.

Affected package: isaaclab_tasks (plus docs, scripts/, .github/workflows/).

Type of change

• Breaking change (existing functionality will not work without user modification)
• Documentation update

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there

[isaaclab-review-bot]

🤖 Isaac Lab Review Bot — Multi-Perspective Review

Updated review — now reflecting head commit 9c59d062 (previously reviewed 877757f7).

Summary

This PR merges the Direct and Manager-based Cartpole task packages into a single isaaclab_tasks.core.cartpole package and removes 35+ deprecated per-variant task IDs. It's a well-executed structural refactor with clear changelog documentation.

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📝 Incremental Changes (since last review at 877757f7)

One new commit (9c59d062 — "Move cartpole golden image tests") with test asset reorganization:

Golden image consolidation:

• Renamed 7 files — per-variant camera task directories (Isaac-Cartpole-Albedo-Camera-Direct-v0/, Isaac-Cartpole-Depth-Camera-Direct-v0/, Isaac-Cartpole-Camera-Presets-Direct-v0/, Isaac-Cartpole-SimpleShading-*-Camera-Direct-v0/) consolidated into a single Isaac-Cartpole-Camera-Direct/ directory
• Removed 2 files — Isaac-Cartpole-RGB-Camera-Direct-v0/ directory deleted (rgb.png and rgba.png now redundant, covered by consolidated directory)

This is purely a test infrastructure change — aligning golden image paths with the new unified task name Isaac-Cartpole-Camera-Direct.

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🧪 Isaac Lab Expert Perspective

Test alignment is correct. Since the deprecated per-variant camera task names (Isaac-Cartpole-Albedo-Camera-Direct-v0, Isaac-Cartpole-RGB-Camera-Direct-v0, etc.) have been merged into Isaac-Cartpole-Camera-Direct, the golden images must also live under that single directory. The rename preserves existing test images without regeneration.

No concerns: The RGB/RGBA images removed from Isaac-Cartpole-RGB-Camera-Direct-v0/ are duplicates of what's now at Isaac-Cartpole-Camera-Direct/default_physics-default_renderer-rgb.png and rgba.png (renamed from the -Camera-Presets- variant).

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🔇 Silent Failure Hunter Perspective

Low risk. If any golden-image test still references the old directory paths, it would produce a clear test failure (file not found), not a silent regression. The consolidation is straightforward.

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✅ Overall Assessment

LGTM — This commit completes the test infrastructure alignment for the task name consolidation. No logic changes, no risk of silent failures. The PR is now fully consistent: code, configs, changelogs, and test assets all reflect the unified naming scheme.

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Update (504e41a): New commit regenerates 4 golden images under Isaac-Cartpole-Camera-Direct/ (albedo, constant_diffuse, diffuse_mdl, full_mdl). Only LFS pointer hashes and minor file-size changes — no code or logic modifications. Still LGTM. ✅