site: real-time /changelog page fed by GitHub Releases (edge function + build fallback + feed) #126

Port the atlas changelog to ui.codeatlas.com.br: Pages Function reads GitHub Releases of codeatlasdev/ui (tags @codeatlasdev/ui@*) at the edge (cache ~1 min, last-good fallback), build-time fallback from packages/ui/CHANGELOG.md, per-version anchors, channel badge, date, sanitized Markdown, npm + release links, special thanks footer, /changelog.json and Atom feed, nav + sitemap + SEO. Unit tests for the lib, Playwright spec, wrangler pages dev proof.