Describe the problem

SvelteKit currently has a heuristic in place which tells Vite which packages are Svelte packages (for noExternal stuff) by looking up the package.json content and seeing if there's a svelte property.

The svelte-kit package command does not currently set this field.

Describe the proposed solution

Use the same logic that is used for the main entry to produce a svelte entry.

Alternatives considered

A workaround for now is for users to specify this field in their package.json themselves as it's copied over as of lately.

Importance

would make my life easier

Additional Information

The svelte key is likely more of a historical thing at this point, and deserves some more thought regarding the new developments, but for now the quick fix is to just add this field