[codex] add deno adapter

[JoviDeCroock]

Summary

• Add @pracht/adapter-deno with a native Deno.serve generated entry, Web Request/Response request handling, static asset serving, document header manifest support, and Deno context hooks.
• Wire Deno into pracht build/pracht preview, including Deno target detection, deno run preview permissions, and an ISG runtime-revalidation warning.
• Update adapter docs, workspace/vision docs, render-mode caveats, the basic example, and add a Deno build-output e2e test.

Testing

• pnpm run build
• pnpm run e2e
• pnpm run format
• pnpm run lint
• pnpm run test
• pnpm run typecheck

Checklist

• Docs updated if needed
• Skills updated if needed (N/A)
• Changeset added if published packages changed