X_FLIGHT_SECOND_CURVE

a module other than packages/core/src/backoff.ts computes its own backoff

it raises a factor to an attempt and clamps the result in one expression, which is a retry curve whatever it is named. Four of these shipped at once — jobs/retry.ts, ai/gateway.ts, realtime/thundering-herd.ts, db/transaction.ts — with three different jitter strategies between them, so fixing a backoff bug meant finding four files and missing three. Matched on SHAPE, never on the name: the first draft looked for a roll called random/rng/roll and read straight past a copy whose parameter was r, the same way a rule spelled RenderMode read past PwaRenderMode

import { backoffDelay } from '@ultimat3/core' and delegate — pass curve and jitter rather than re-deriving them