* feat: add headless CMS reference and integration guides
Add CMS selection guide, content modeling patterns, and editorial
workflow reference for marketers. Add integration guides for Sanity
(GROQ API), Contentful (CDA/CMA), and Strapi (v5 REST). Register
all three in REGISTRY.md and link from content-strategy skill.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
* fix: address review feedback on headless CMS guides
- Use {curly_brace} placeholder convention for Strapi relation example
- Add note that Contentful CMA create uses PUT with client-generated ID
- Add URL-encoding note for Sanity GROQ query parameter
- Switch Sanity mutation example from createOrReplace to create (no _id needed)
- Add Content-Type header to Contentful update entry example
- Fix outdated "Assembly" product name to "Studio" for Contentful
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>