Compare agent skills before installing.

Owns the `tests/` folder of an ML workspace and the pairing rule between an experiment and its tests. Lightweight router: every test category has its own subskill (`smoke-test-ml-pipeline` is the only one for v1; `regression-test-ml-pipeline` / `distribution-test-ml-pipeline` etc. plug in as siblings as the workspace grows). This skill places an empty `tests/<category>/` folder, enforces the stem-pairing rule between `tests/<category>/test_NN_<short_name>.py` and `experiments/NN_<short_name>.py`, and dispatches to the matching subskill when the user asks for a test. TRIGGER when: a new design note was just approved by `iterate-ml-experiment` and the matching test has to be drafted before the experiment can be marked done; the user asks "write the smoke test for `02`", "add the regression test", "do we have a test for X?"; an experiment script was edited and the paired test needs revisiting; about to run `pytest tests/` and one of the expected paired tests is missing. SKIP when: the des

Apple's approach to interface design and fluid, physical motion, translated for the web. Use when building or reviewing gesture-driven UI, spring animations, drag/swipe/sheet interactions, momentum and interruptible transitions, translucent materials and depth, typography (optical sizing, tracking, leading), reduced-motion, or the design foundations (feedback, spatial consistency, restraint) behind Apple-style interfaces.