The API reference layout loaded Redoc from the `latest` CDN URL, which
now serves Redoc 3.0.0. That bundle is an ES module that uses
import.meta, so the classic script tag fails with "Cannot use
'import.meta' outside a module" and the Engine, Hub, and Registry API
pages render blank. Pin to the 2.x UMD build.
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>