Refresh SSG prerender without Vite Build

Describe the problem

Right now it's not possible to run SSG without always building/bundling both the app & ssr bundle for production.

If no changes have been made to the frontend source, there's no current way to say "just update the prerendered set of pages".

In other words, if only the backend changes, then we shouldn't have to rebundle everything just to regenerate these pages.

Describe the proposed solution

A way to simply rerun the prerendering step independent of the bundling step, since bundling takes a long time.

I think this is independent of incremental build, since we want to "build" again, but not waste effort bundling if we don't have to.

Alternatives considered

I've looked at https://github.com/sveltejs/kit/issues/2369 but this still will go through the entire bundle/build.

Importance

would make my life easier

Additional Information

I have a website that periodically refreshes pages when content changes (only updates a few times a month). I'd like it so I don't have to waste too much time when changes are made to rerender these pages, since the backend will update much more often than the frontend source.

Start by tracing how SSG prerendering is coupled to the Vite production app and SSR bundle builds. Compare the proposed behavior with issue 2369 and incremental build issue 661; done means a documented or implemented way to rerun prerendering after backend changes without rebundling unchanged frontend sources.