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>

examples/samples/meeting-notes.md

@@ -0,0 +1,28 @@
+---
+skill: meeting-notes
+title: Meeting Notes
+input: "Transcript of a 30-min product/eng sync: debated whether to delay the checkout launch over a payments edge case; agreed to ship behind a flag to 10% on Thursday; Priya to write the rollback runbook; Sam worried about PCI scope; decided to ask Legal by Tuesday."
+source: representative example (hand-written)
+---
+
+# Product / Eng Sync — Checkout Launch
+
+**Date:** (meeting date) · **Attendees:** Product, Eng, (Priya, Sam) · **Purpose:** Decide checkout launch timing
+
+## Decisions
+- ✅ **Ship checkout behind a feature flag to 10% of traffic on Thursday** — not a full launch, to contain the payments edge case.
+- ✅ **Confirm PCI scope with Legal before expanding past 10%.**
+
+## Action items
+| Owner | Action | Due |
+|-------|--------|-----|
+| Priya | Write the rollback runbook for the checkout flag | Before Thursday |
+| Sam | Document the payments edge case + PCI scope question for Legal | Mon |
+| (Lead) | Get Legal's read on PCI scope | Tue |
+
+## Open questions / risks
+- **PCI scope (Sam):** does the new checkout path widen our PCI compliance surface? Blocks expansion beyond 10%.
+- **Edge case:** the payments failure path isn't fully characterised — the 10% rollout is partly to observe it in production.
+
+## Not decided
+- Full-launch date — gated on the 10% results and Legal's answer.