Use $lib/server instead of $lib for db and auth

[galaczi]

I am new to SvelteKit so I am not entirely familiar with the consequences, but shouldn't the db and auth modules be in $lib/server instead of just $lib?

https://kit.svelte.dev/docs/modules#$lib-$lib-server

The Lucia docs do it that way too:

https://lucia-auth.com/getting-started/sveltekit/

[Bloeckchengrafik]

Seems like a good idea to move them!

[JustinyAhin]

@galaczi @Bloeckchengrafik do you want to open a PR with that change?