Move `wizard` out of in-progress into `engineering/` and wire it up as a
promoted skill: plugin.json entry, top-level + Engineering READMEs under
User-invoked, a docs page at docs/engineering/wizard.md, and a Standalone
route in ask-matt for the steps only a human can take.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
