Astro 6.0

Astro 6 launches with a redesigned dev server powered by Vite's Environment API, enabling exact production runtime during development (including Cloudflare Workers, Bun, Deno). Key additions include a built-in Fonts API for self-hosted font optimization, stable Live Content Collections for request-time content fetching without rebuilds, and a stable Content Security Policy API with automatic script/style hashing. The release also upgrades core dependencies to Vite 7, Shiki 4, and Zod 4, and requires Node 22+. Experimental features include a new Rust-based .astro compiler (replacing the Go compiler), queued rendering with up to 2x speed improvement, and a platform-agnostic route caching API with cache invalidation tied to live content collections.