Site APIs moved to the active edge worker

What changed

• Added edge handlers for checkout, experiments, forms, links, recording, tracking, and sync.
• Added privacy, CORS, bot filtering, and rate-limit support libraries.
• Updated the Astro site worker, middleware, and environment typing.
• Expanded publish and artifact services for the new edge path.

Why it matters

Published sites can now run more of their interactive behavior close to visitors through the active edge worker. This is foundational infrastructure for fast customer sites with connected forms, tracking, links, checkout, and experiments.