## Description

This PR introduces the SkillGen framework to Isaac Lab, integrating GPU
motion planning with skill-segmented data generation. It enables
efficient, high-quality dataset creation with robust collision handling,
visualization, and reproducibility.

**Note:** 
- Please look at the cuRobo usage license
![here](docs/licenses/dependencies/cuRobo-license.txt)
- Please look at updated isaacsim license
![here](docs/licenses/dependencies/isaacsim-license.txt)

### Technical Implementation:

**Annotation Framework:**
- Manual subtask start annotations to cleanly separate skill execution
from motion-planning segments
- Consistent trajectory segmentation for downstream dataset consumers

**Motion Planning:**
- **Base Motion Planner (Extensible):**
   - Introduces a reusable planner interface for uniform integration:
-
`source/isaaclab_mimic/isaaclab_mimic/motion_planners/base_motion_planner.py`
   - Defines a minimal, consistent API for planners:
- `update_world_and_plan_motion(...)`, `get_planned_poses(...)`, etc.
   - The cuRobo planner inherits from this base class.
- New planners can be added by subclassing the base class and
implementing the same API, enabling drop-in replacement without changes
to the SkillGen pipeline.
 
- **CuRobo Planner** (GPU-accelerated, collision-aware):
  - Multi-phase planning: approach → contact → retreat
  - Dynamic object attach/detach and contact-aware sphere management
  - Real-time world synchronization between Isaac Lab and cuRobo
  - Configurable collision filtering for contact phases
  - **Tests**:
-
`source/isaaclab_mimic/isaaclab_mimic/motion_planners/curobo/test/test_curobo_planner_cube_stack.py`
-
`source/isaaclab_mimic/isaaclab_mimic/motion_planners/curobo/test/test_curobo_planner_franka.py`
    - `source/isaaclab_mimic/test/test_generate_dataset_skillgen.py`

**Data Generation Pipeline:**
- Automated dataset generation with precise skill-based segmentation
- Integrates with existing observation/action spaces
- Supports multi-env parallel collection with cuRobo-backed planning

**Visualization and Debugging:**
- Rerun-based 3D visualization for trajectory/collision inspection
- Real-time sphere visualization for collision boundaries and contact
phases

### Dependencies:
- **cuRobo**: motion planning and collision checking
- **Rerun**: 3D visualization and debugging

### Integration:
This extends the existing mimic pipeline and remains backward
compatible. It integrates into the manager-based environment structure
and existing observation/action interfaces without breaking current
users.

## Type of change
- [x] New feature (non-breaking change which adds functionality)
- [x] This change requires a documentation update

## Screenshot

### SkillGen Data Generation

<table>
  <tr>
<td align="center"><strong>Cube Stacking SkillGen Data
Generation</strong></td>
<td align="center"><strong>Bin Cube Stacking SkillGen Data Generation
(Using Vanilla Cube Stacking Source Demos)</strong></td>
  </tr>
  <tr>
    <td>
<img
src="https://github.com/user-attachments/assets/de240b89-e670-4035-84ae-4101a4f70dae"
           alt="Cube Stacking Data Generation"
           style="width: 480px; height: 270px; object-fit: contain;">
    </td>
    <td>
<img
src="https://github.com/user-attachments/assets/dd94e0a6-ad1b-4366-80c4-7ff96cabeb3e"
           alt="Bin Cube Stacking Data Generation"
           style="width: 480px; height: 270px; object-fit: contain;">
    </td>
  </tr>
</table>

### Bin Cube Stacking Behavior Cloned Policy

![bin_cube_stack_bc_policy](https://github.com/user-attachments/assets/d577d726-d623-4b27-90e5-a047cd67e4f9)

### Rerun Integration

![rerun_skillgen](https://github.com/user-attachments/assets/9c469bc4-d3f6-465a-8ca6-0ddfd85c6ad0)

### Motion Planner Tests

<table>
  <tr>
    <td align="center"><strong>Obstacle Avoidance (cuRobo)</strong></td>
<td align="center"><strong>Cube Stack End-to-End (cuRobo)</strong></td>
  </tr>
  <tr>
    <td>
<img
src="https://github.com/user-attachments/assets/a022342f-4c4e-42ea-a48c-cb1ea65c94db"
           alt="Obstacle Avoidance cuRobo"
           style="width: 480px; height: 270px; object-fit: contain;">
    </td>
    <td>
<img
src="https://github.com/user-attachments/assets/7e6290b6-8322-4702-ae2f-f363a87badde"
           alt="Cube Stack End-to-End cuRobo"
           style="width: 480px; height: 270px; object-fit: contain;">
    </td>
  </tr>
</table>

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

---------
Signed-off-by: Kelly Guo <kellyg@nvidia.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>
Co-authored-by: Pascal Roth <57946385+pascal-roth@users.noreply.github.com>