Add package.exports to @zenstack/server

[krist7599555]

Many bundler with mixed esm/cjs will not work without exports field in package.json

[ymc9]

Thanks for making this PR @krist7599555 !

I'm thinking maybe we should really generate cjs/esm dual format during build (like already done in the runtime package with tsup). I'm not really an expert on bundlers. Do you feel that to be necessary?

[krist7599555]

@zenstack/server will mostly be use with framework like next, sveltekit which have another step to build production. And output is likely to be esm with import syntax.

So, I suggest using tsup with minify=false is the way.

If @ymc9 agree I welcomely to create pull request about Migrate
@zenstack/server to tsup for you. (breaking!! change because npm folder structure will nested 1 level)

from

package.json
api/base.js
api/rest/index.js
api/rpc/index.js
api/utils.js
express/index.js
express/middleware.js
fastify/index.js
fastify/plugin.js

to

package.json
dist/api/base.js
dist/api/rest/index.js
dist/api/rpc/index.js
dist/api/utils.js
dist/express/index.js
dist/express/middleware.js
dist/fastify/index.js
dist/fastify/plugin.js

[ymc9]

The "package.json" file has a publishConfig setting:

    "publishConfig": {
        "directory": "dist",
        "linkDirectory": true
    }

So when published, the content of "dist" will be deployed instead of the root folder. I think we don't need the "dist" level in the "exports" section.

I'm not even sure if cjs/ems dual output is necessary. If framework bundlers are fine with CJS we can probably keep it as is. Just curious, with what framework did you initially run into issues with the "exports" section missing?