Turnstile
The simulated back-office. Admissions recorded here are not visible to anything until an admission poll reads them — the same delay a real integration has.
Invent a member
Walk somebody through a turnstile
Break the back-office
Makes every call fail. A member whose plans already synced stays authorized — the deciding PBC reads its own projection and never calls out on the redemption path. That is what the projection is for, and this is how it gets proved rather than argued.