Feature: Signup / Signin with Google

[bensivo]

Basic local implementation is done, but we need to do these before calling this finished:

• Write unit tests for JWT auth
• Find a way to get JWT tokens from a local script, so we can implement e2e testing
• Create Supabase and GCP projects for mapo-prod

[bensivo]

Implemented basic e2e tests for JWT auth.

Next, need to update the Files API so it's scoped to each individual user.