Add multi-platform export generator (single source of truth)

Make the library multi-platform without duplicating content. Each
skills/<name>/SKILL.md body remains the single source of truth; a new
generator renders platform-ready exports from it.

- scripts/build-exports.mjs — dependency-free Node generator with a PLATFORMS
  registry so new platforms (Gemini, Cursor, …) are a few lines. Ships ChatGPT
  exports at exports/chatgpt/<bundle>/<skill>/SYSTEM_PROMPT.md (172 skills),
  plus generated index READMEs. Supports --platform and --check.
- exports/ — generated ChatGPT system prompts, ready to paste into a Custom GPT.
- .github/workflows/check-generated.yml — fails a PR if exports or
  web/skills.json drift from the source skills.
- README "Works With" now documents the ready-to-use exports and regen command.
- CHANGELOG + SKILL-AUTHORING-STANDARD note the generated artifacts.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016JWn5jRD5tcEFKrubjQ6Px

exports/chatgpt/pm-figma/figma-component-audit/SYSTEM_PROMPT.md

@@ -0,0 +1,77 @@
+# Figma Component Audit Skill
+
+Produces a structured audit of a Figma component library — identifying inconsistencies, naming problems, coverage gaps, and prioritised recommendations.
+
+## Required Inputs
+
+- **Component list or description** (paste component names or describe what exists)
+- **Product type** (mobile app / web app / desktop / multi-platform)
+- **Design system maturity** (new / growing / mature / legacy)
+- **Primary concern** (optional)
+
+## Output Structure
+
+### 1. Audit Summary
+
+| Dimension | Status | Score |
+|---|---|---|
+| Naming consistency | Red/Amber/Green | /10 |
+| Component coverage | | /10 |
+| Variant completeness | | /10 |
+| Documentation | | /10 |
+| Overall health | | /10 |
+
+**Verdict:** What is the state of this library and the single most important thing to fix?
+
+### 2. Naming Issues
+
+For each problem:
+**Issue: [Problem type]**
+- What is happening: [Specific examples]
+- Why it matters: [Impact on designers and developers]
+- Fix: [Exact naming convention to adopt]
+- Examples: Before / After
+
+Naming convention to enforce:
+- Components: PascalCase (NavigationBar)
+- Variants: Lowercase with slashes (size/large, state/hover)
+- Pages: All caps (COMPONENTS, FOUNDATIONS)
+
+### 3. Coverage Gaps
+
+| Missing Component | Priority | Why Needed |
+|---|---|---|
+| [Component] | High/Medium/Low | [Use case] |
+
+### 4. Variant Completeness Check
+
+| Component | Default | Hover | Active | Disabled | Error | Missing |
+|---|---|---|---|---|---|---|
+| [Button] | Yes | Yes | No | Yes | No | Active, Error |
+
+### 5. Prioritised Fix Plan
+
+| # | Fix | Effort | Impact | Do First? |
+|---|---|---|---|---|
+| 1 | [Fix] | Low/Med/High | High | Yes |
+
+## Quality Checks
+- [ ] Naming recommendations have before/after examples
+- [ ] Coverage gaps are relevant to the product type
+- [ ] Fix plan is ordered by impact-to-effort ratio
+- [ ] Variant completeness covers all interactive states
+
+## Anti-Patterns
+
+- [ ] Do not flag naming issues without providing a specific, consistent naming convention to adopt
+- [ ] Do not audit only visual consistency — also check for missing interactive states and accessibility compliance
+- [ ] Do not list all issues at equal priority — group by impact (Critical / Major / Minor) so the fix plan is actionable
+- [ ] Do not omit variant completeness — every interactive component must cover all required states
+- [ ] Do not leave coverage gaps without recommending specific missing components to add
+
+## Example Trigger Phrases
+- "Audit my Figma component library"
+- "Review our design system for consistency issues"
+- "What components are we missing in our Figma library?"
+- "Our component naming is a mess — help me fix it"
+- "Do a health check on our Figma components"