Expand description
Terminal execution retention scanner.
Scans ff:idx:{p:N}:lane:<lane>:terminal for each partition+lane,
finding terminal executions older than the configured retention
period. For each batch the per-execution cascade-delete runs
through EngineBackend::trim_retention (Valkey lifts the pre-
PR-7b direct-client path; Postgres cascades DELETEs across every
sibling table inside one transaction; SQLite is Unavailable per
RFC-023 Phase 3.5).
Retention trimming is inherently a scan-and-delete loop over time. The trait exists to remove engine-side Valkey coupling, NOT to atomise the operation into a single round-trip — implementations may still issue multiple round-trips per batch.
Reference: RFC-010 §6.12