fix(cloudflare): remove worker output for fully static sites

[matthewp]

Changes

• Fully static Cloudflare sites no longer output unnecessary _worker.js directory
• Detects fully static sites by checking if all non-internal routes are prerendered in astro:routes:resolved
• Removes _worker.js directory in astro:build:done for static sites
• Changes staticOutput adapter support from 'unsupported' to 'stable'

Testing

• Added new test fixture packages/integrations/cloudflare/test/fixtures/static/ with a fully static site
• Added static.test.js that verifies _worker.js directory is not present after build
• All existing Cloudflare tests pass

Docs

No docs changes needed - this is a bug fix that makes static sites work as expected without generating unnecessary server code.

[changeset-bot]

🦋 Changeset detected

Latest commit: ef1e700

The changes in this PR will be included in the next version bump.

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[mikepage]

Hi @matthewp

When I was working on the build pipeline for multi-tenant astro projects with Cloudflare Workers for Platforms I noticed the worker entry file went gone when building static with the updated @astrojs/cloudflare@13.0.0-beta.8 adapter.

Cloudflare Workers for Platforms requires a minimal module to serve static assets, similar to the module we got in the build output.

I wrote an adapter for Cloudflare Worker for Platforms to always generate this module and
add a fix where assets are served without content type (inspired by https://github.com/cloudflare/vibesdk/)

Failed to load module script: Expected a JavaScript-or-Wasm module script but the server responded with a MIME type of "". Strict MIME type checking is enforced for module
scripts per HTML spec.

See the adapter:
https://github.com/mikepage/astro-workers-for-platforms-example-theme/blob/main/adapter.mjs

The build worker based on examples from Cloudflare:
https://github.com/mikepage/astro-workers-for-platforms-example-build-worker/

Do you think a minimal adapter like this is nice for deploying multi-tenant, or should we just make some code use server to generate the server endpoint. Then we just need to fix the Content-Type header issue.