cloudflare/workers-sdk @cloudflare/playground-preview-worker@0.3.1 on GitHub

#12655 a31ee0b Thanks @petebacondarwin! - Migrate workers-playground from Cloudflare Pages to Cloudflare Workers
Replace the Cloudflare Pages deployment with a Workers + static assets deployment.
In production (wrangler.jsonc), this is an assets-only Worker with no code entry point — the playground-preview-worker handles all routing and proxying in front of it.
For local development, a separate config (wrangler.dev.jsonc) adds a Worker entry point (src/worker.ts) that replicates the proxying behavior of the production playground-preview-worker. It proxies /playground/api/* requests to the testing playground-preview-worker, and for the /playground route it fetches an auth cookie from the testing endpoint, transforms it for local use (stripping SameSite/Secure directives and replacing the testing origin with localhost), and injects it into the response so the preview iframe can authenticate.
The playground-preview-worker referer allowlist is updated to also accept requests from *.workers-playground.workers.dev (in addition to the existing *.workers-playground.pages.dev).