Implement Cloud SQL Auth Proxy

[taterhead247]

Right now the Postgres database is exposed to the internet. We need to lock that down. The recommended approach is having your Firebase project leverage Auth Proxy for Cloud SQL. This sets up a private tunnel from your app to the database.

Here is some reading material:
https://docs.cloud.google.com/sql/docs/mysql/sql-proxy
https://oneuptime.com/blog/post/2026-02-17-how-to-connect-firebase-to-cloud-sql-for-relational-database-access/view

Let me know what you need!