Supabase Branching

this has been an ongoing effort to add branching support to several tools in the Supabase stack. We spent a lot of time adding multi-tenancy to the key tools and figuring out a good security model for development branches

for this initial release we've focused on GitHub and Vercel, and we'll eventually add other providers.

The database aspect works as you'd probably expect - we use migrations (managed by our CLI) to make updates to Preview Branches. when a PR is merged we run the migrations against the production database

this is the 3rd major release this week - we have a few more on Friday that will fit into the "branching" story