feat: workflow recipes, eval badges, one-click MCP, playground upgrades, sample gallery, skill-of-the-week

Signature features that turn breadth (174 skills) into a differentiated product:

- Workflow recipes: 5 cross-profession chains (workflows.json) that pass each
  output forward — slash commands (/ship-a-feature etc.), WORKFLOWS.md generated
  by scripts/build-workflows.mjs, README + MCP (list_workflows/get_workflow) wired
- Eval-backed quality: real per-skill scores from evals/results.json surfaced as
  badges in the playground and an honest README section (6 scored skills)
- One-click MCP: 'claude mcp add' install + workflow tools, works in any MCP client
- Playground: 'which skill?' recommender, with/without compare toggle, shareable
  ?skill= deep-links with prefilled inputs
- Sample-output gallery: hand-written examples for the hero five + generator
  (scripts/build-samples.mjs) + web/examples.html
- Skill-of-the-week: scheduled workflow + script that composes X/LinkedIn posts
  and posts to an optional webhook

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/launch-posts.md

@@ -127,7 +127,15 @@ Key links:
 
 ---
 
-## 6. Ongoing distribution checklist
+## 6. Skill of the week — automated
+
+A scheduled GitHub Action (`.github/workflows/skill-of-the-week.yml`) picks a featured skill every Monday, rotating deterministically through the production-tier skills, and composes ready-to-post X + LinkedIn copy. The text always appears in the Action's **job summary** so you can copy-paste it.
+
+**To fully automate posting:** add a repo secret `POST_WEBHOOK_URL` pointing at a Zapier / Make / Buffer / Slack incoming webhook. The script POSTs `{ text, linkedin, skill, link }` to it each week — wire that webhook to publish to X/LinkedIn.
+
+Run it any time locally: `npm run skill-of-the-week`.
+
+## 7. Ongoing distribution checklist
 
 - [ ] Submit to the [skills.sh](https://skills.sh) / Claude skills directories and any "awesome-claude" lists
 - [ ] Add a `topics` set on the GitHub repo (claude, claude-code, ai-agents, prompt-engineering, productivity)