All islands now render server-side:
- freeze.sx loaded into kernel (freeze-scope for home/stepper)
- Browser-only APIs stubbed (local-storage-get/set, dom-listen,
dom-dispatch, dom-set-data, dom-get-data, promise-then)
→ return nil on server, client hydrates with real behavior
Zero island failures. Both layouts/header and home/stepper render
with hydration markers, CSS classes, and initial signal values.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>