Islands now always emit <span data-sx-island="name"> placeholder
instead of attempting SSR. Island bodies contain client-only symbols
(signals, DOM refs) that cascade errors during native render.
Component-defs moved to /static/sx-components.sx endpoint instead of
inline <script> — avoids </script> escaping issues that broke the
client-side SX parser.
Remaining: client WASM kernel not loading components from external
endpoint (expects inline script tag). Need to configure client boot
to fetch from /static/sx-components.sx.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>