Move the Vue app from Cloudflare Pages to a Worker with static assets #126

The Vue app deploys to Cloudflare Pages through .github/workflows/deploy-cloudflare.yml (wrangler-action, command: pages deploy ... --project-name=factoriotools). Cloudflare now says to start new projects on Workers, and it has a guide for moving Pages projects over. Pages is not deprecated, so there is no deadline. This is housekeeping, found by a cross-repo sweep on 2026-09-25.

Guide: https://developers.cloudflare.com/workers/static-assets/migration-guides/migrate-from-pages/

What moves

• src/vue/public/_worker.js becomes the Worker's main. It is a Pages "advanced mode" Worker, and the guide covers this case. Move it out of public/, so it is not also uploaded as an asset. Point main at it, and set "assets": { "directory": "<build>/dist", "binding": "ASSETS" }. The env.ASSETS.fetch calls keep working.
• The SPA fallback. The script returns the 404.html shell with status 404 for client-side routes like /oil-field. That can stay as it is. The built-in "not_found_handling": "single-page-application" is simpler, but it serves index.html with status 200, which changes what crawlers see. Pick one on purpose.
• The old-host redirect. The script 301s factoriotools-5jg.pages.dev to oilfieldplanner.factorygamefan.com. A Worker never receives requests for a pages.dev host. So either keep the Pages project alive as a redirect-only stub, or accept that the old host stops redirecting.
• Workflow: change command: to deploy (plus --config if wrangler.jsonc does not sit next to the build). Pull requests already build without deploying, so that part stays.
• Domain: oilfieldplanner.factorygamefan.com is a proxied CNAME to the Pages project. Add it as a Custom Domain on the Worker, which replaces that record. Touch no other factorygamefan.com records.
• Previews. Pages made a preview URL for each branch. For the same on Workers, set "preview_urls": true. That is optional here, since the workflow only deploys main.

Done when

• https://oilfieldplanner.factorygamefan.com/ and a hard load of /oil-field both work from the Worker.
• A decision is written down for the factoriotools-5jg.pages.dev redirect.