Investigate Deploy Process Refinements

We've run into some pain points with our deployment process recently, especially around rollbacks - we should look into ways to make this process smoother in order to de-risk deploys and improve the developer experience.

Ideally, we're not looking for heavy changes here.

Some options to improve on this front include, but aren't limited to:
- Documentation around the revert process to make rolling back a bad build more straightforward
- A manual QA plan that lists the major workflows (which can ideally be used to prioritize flows for E2E tests)
- Use tags for prod deploys instead of merging to a `prod` branch (so deploys are just pushing a new tag and rollbacks are just pushing the previous one - this might be easier to reason about than stacked reverts)
- Very open to other ideas here