Add Apple Notes Snapshot control-room skill

[xiaojiou176]

Summary

• add a public notes-snapshot-control-room skill under skills/
• include a README for discoverability and human-facing usage notes
• register the skill in marketplaces/default.json

Why

This adds a reusable public skill for keeping Apple Notes Snapshot host integrations truthful without overstating product scope, attach proof, or marketplace status.

Validation

• uv sync --group test
• uv run pytest -q tests/test_skills_have_readme.py tests/test_sdk_loading.py

[enyst]

Hey @xiaojiou176 , thank you for the PR!

Could you please tell more about the apple notes snapshot and what is the intended learning for agents from this skill?

It seems the contents of the skill is more about what it's not, than teaching the agent what to do or how to use or when to use?

[xiaojiou176]

Superseded by #150, which carries the current Apple Notes public-skill packets for both notes-snapshot-control-room and notestorelab-case-review. Closing this older snapshot-only draft to keep the review surface on one thread.