Create dev / prod versions using compile-time constants and tree-shaking

[AndrewPrifer]

Currently we simply have two different entry points, 1 for dev, 1 for prod. Use the define config property and tree-shaking instead. Have a conditional config we can run twice for each target. This will scale better to when we want to alter things deeper in the import hierarchy anyway, like stripping UI code from createThreeGizmo().

https://tsup.egoist.dev/#conditional-config
https://tsup.egoist.dev/#compile-time-environment-variables
https://tsup.egoist.dev/#custom-esbuild-plugin-and-options

If treeshaking is not working, try the treeshake option which runs Rollup on the output:
https://tsup.egoist.dev/#tree-shaking