{session scope, ordinal} - the compact dedup key ADR-0059 decision 3 blesses, read off the stored %Statifier.Effect.SendDelayed{}.

ADR-0059 amended ADR-0054 decision 3: %SendDelayed{} and %Cancel{} carry a per-execution ordinal minted from a session-global, monotone counter, so {session scope, ordinal} is unique on its own. This package stores that pair as the key; the remaining components of the documented compound form - send_id, macrostep, microstep, round, c_index, owner - stay row data on the stored effect rather than key components. Both forms are conformant; the compound form remains upstream's documented default because it is self-describing in a store, and this package keeps that self-description by storing the effect itself alongside the key.

Both components are deterministic as of scheduling rather than firing: the ordinal is pure fold state (ADR-0059 decision 2), so re-executing the same drive after a crash rebuilds a byte-identical key. Cancellation never addresses this key - spec 6.3 cancels every timer under a sendid, and send_id is row data here, so a cancel matches rows via StatifierOban.Timer.Key.cancels?/3.