New tool at tools/xpace-server — simulates the Ubox messaging
infrastructure locally. Features: WebSocket relay, static file serving
for apps/, automatic UboxClient shim injection (with crypto.randomUUID
polyfill for HTTP contexts), LAN-accessible URLs, and a live dashboard
showing connected clients, shared variables, and message log.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>