I run EdgeKits on the full Cloudflare stack, and the marketing site is mostly Astro with a handful of React islands - a newsletter form, a toaster, a desktop nav. Astro 6 moved the dev server into workerd so local development finally mirrors production. I expected a version bump. I got an afternoon of debugging. Here is every error I hit, in the order I met it, with the log that produced it, why it happened, and the exact fix. If you are doing an Astro 5 to 6 migration with React islands on Cloudflare Workers, this is the map I wish I'd had. My stack: Astro 6.3.6, @astrojs/cloudflare 13.5.x, @astrojs/react 5.0.5, React 19, Vite 7, Tailwind 4, output: 'server' on Workers. First wall: the Vite dependency scan crashes The very first npm run dev printed this before the server was even ready: [ERROR] [vite] (!) Failed to run dependency scan. Skipping dependency pre-bundling.…