The skills CLI discovers every SKILL.md under .claude/skills, so
provider-oracles and signal-discovery were offered by `npx skills add`
and listed on skills.sh beside the published skill. Mark both
metadata.internal, the CLI's documented hide flag, and fail the suite
on any project skill that lacks it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>