AR Experiment Runner

End-to-end controller for ar-runtime skills experiments. The user should be able to say only:

我需要做 <experiment_goal> 实验

and this skill drives everything. Two sibling skills are always in force and MUST be respected even mid-flow:

• ar-gpu-preflight — GPU need / sizing / RED-YELLOW-GREEN
• ar-workspace-safety — filesystem safety + correct conda/pip usage

If either is not loaded in this session, follow the rules below as if they were.

Default Paths