feat: graduate wizard into the engineering bucket

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>

skills/in-progress/README.md

@@ -3,7 +3,6 @@
 Skills that are still being developed. They're not ready to ship — expect rough edges, breaking changes, and abandoned experiments. They're excluded from the plugin and the top-level README until they graduate to a stable bucket.
 
 - **[loop-me](./loop-me/SKILL.md)** — Grill yourself into implementable workflow specs over multiple sessions, using the current directory as a stateful workspace. User-invoked.
-- **[wizard](./wizard/SKILL.md)** — Generate an interactive bash wizard that walks a human through a manual procedure (setup, a one-off migration, a state transition) — opening URLs, capturing values, writing `.env` and GitHub Actions secrets. User-invoked.
 - **[writing-beats](./writing-beats/SKILL.md)** — Shape an article as a journey of beats, choose-your-own-adventure style. Pick a starting beat, write only that beat, then pivot to the next, until the article reaches a natural end.
 - **[writing-fragments](./writing-fragments/SKILL.md)** — Grilling session that mines you for fragments — heterogeneous nuggets of writing — and appends them to a single document as raw material for a future article.
 - **[writing-shape](./writing-shape/SKILL.md)** — Take a markdown file of raw material and shape it into an article paragraph by paragraph, arguing format choices at each step.