A crashed island renders its error in dev and nothing in prod, leaving
the surrounding server-rendered page intact.
Island .tsx sources carry an explicit @jsxImportSource react pragma: the
repo's root tsconfig points jsxImportSource at @wrnexus/core, so without
it island JSX compiles to WRNexus's string renderer instead of React
elements.
Tests render on the client via createRoot rather than a server renderer,
because React error boundaries do not engage during SSR — and islands
are client-only regardless.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
