Build, debug, and review Eleventy v3 sites and Nunjucks templates, including the Build Awesome v4 prerelease migration. Use when asked to "create an 11ty page", "add a Nunjucks filter", "fix my layout chain", "review my .njk template", "set up Eleventy", "migrate to Build Awesome", or "audit my static site"; when `package.json` includes `@11ty/eleventy` or `@awesome.me/buildawesome`; when paths include `.eleventy.js`, `eleventy.config.js`, `.njk`, `.11tydata.js`, `.data.js`, `.11ty.js`, or `.server.js`; or when debugging Nunjucks rendering or Eleventy data cascades, filters, shortcodes, and security. Generic static-site/security topics and `.data.js`/`.server.js` names require confirmed Eleventy or Build Awesome context; standalone Nunjucks work is also in scope.