Asset previews run here, on their own origin, so uploaded code can never read the main site’s storage (SYSTEM-CONTRACT §3, §9). Every surface speaks fx-preview/v1 and is mounted in a sandbox="allow-scripts" iframe with no same-origin access. Nothing a preview needs is fetched from a third-party origin at runtime: an opaque-origin frame cannot finish loading one, so the parser stalls before the bridge runs and the surface dies without a word. This page is not a preview.
Built by tools/build-preview-dist.mjs. 16 surfaces, 17 vendored third-party file(s).