auth in remix + pocketbase

[xuatz]

Implement mvp auth feature for xbo, which means:

• /create
• /login
• redirect to /home on auth
• setup pocketbase to save user information

Can take a look at https://github.com/sergiodxa/remix-auth to see if it makes sense to use this, or if we should just DIY.

Some future consideration is that we will want to support password reset, by sending their registered email a random string, where they can input it on /reset. But we will do that in future in #37

Technically I already previously integrated SuperTokens to some degree, which had many many useful auth features implemented, but it didn't feel like a first class citizen when using with remix. Could take a 2nd look but probably simpler to make a basic local solution for now.