Server runtime optimizer turns on prebundling in Vite's unused Node ssr environment #412

Summary

In apps where Void owns the workerd runtime, #407's optimizeDeps.include: ['void > email-validator'] goes to every non-client environment. In default (no-framework) mode that includes Vite's built-in Node ssr environment, which these apps never use, because the app runs in void_worker.

Cause

Vite turns off the dep optimizer for server environments only when noDiscovery && !include.length. A non-empty include therefore starts an optimizer for ssr, and DevEnvironment.listen() waits for it to finish. The result is an extra optimizer pass at dev startup and an extra node_modules/.vite/deps_ssr cache directory.

This contradicts the comment in createServerRuntimeOptimizerPlugin, which says forcing an include on a Node environment "turns on SSR prebundling the framework did not ask for".

Impact is small: nothing breaks. React pages mode already turns on the ssr optimizer, so this mainly affects other no-framework apps.

Reproduction

On playground/spa (or any API-only app), run rm -rf node_modules/.vite && vp dev. node_modules/.vite/deps_ssr/_metadata.json now exists and lists void > email-validator. Before #407 there was no deps_ssr.

Suggested fix

Add the include only to the environments the Cloudflare plugin runs in workerd: void_worker in default mode, the configured viteEnvironment and its child environments for class-a frameworks, and auxiliary workers. Every other non-client environment keeps just exclude: ['void']. Add a unit case asserting the default-mode ssr environment resolves to { optimizeDeps: { exclude: ['void'] } }.