✨ feat: Add auth flow (#146)

This adds a simple way to incorporate a centralized authentication flow.

The idea is to have the user, API and SSH (for machine authentication)
all in one place using `openauthjs` + `SST`

We also have a database now :)

> We are using InstantDB as it allows us to authenticate a use with just
the email. Plus it is super simple simple to use _of course after the
initial fumbles trying to design the db and relationships_

packages/functions/partykit.json

@@ -0,0 +1,6 @@
+{
+  "$schema": "https://www.partykit.io/schema.json",
+  "name": "nestri-party",
+  "main": "src/party/index.ts",
+  "compatibilityDate": "2024-12-31"
+}