Update: Supabase support came through and successfully recovered the database. Our site is back online and no data was lost.

The Supabase dashboard is still experiencing errors and won't load properly, but the underlying data and API are intact.

Thank you to the HN mods for un-flagging this, and to everyone who took a look. Hopefully, we'll receive a post-mortem from Supabase on the exact cause of the disk downgrade issue during the PG update.