[Shopping List] Task 3a - CI/CD via GitHub Actions

[akisma]

This needs to be deployable so that my business partner can view it from his Android phone, remotely. He lives very far away and won't be able to test locally with me. We have existing AWS and Vercel accounts, and can use whichever is the easiest to bootstrap. We'll worry about production hardening much later, this is early stage development. We should always bias towards IAC/DRY/repeatable and avoid deterministic configurations. We should leverage GitHub Actions if they will help us with our build.