D2 · v2 is a rebuild, with a one-shot migration rehearsed nightly

Accepted · 2026-09-30 · zuki · Partly superseded by D17, D19, D20, D21 and D25 · Detail: [Decision] v2 rebuild with a one-shot rehearsed migration

A new app and a new Supabase project on schema V13. The full migration runs every night on a copy of v1 production; the data moves once, on a cutover weekend; v1 stays read-only as the way back.