Opus finding
Backfill edge case contradicts 'cohort cache freshness' invariant on first-ever run
lowdocs-gapmedium
- skills/fork-first-run-alert/SKILL.md:174-178
The edge case says to set announced_at to today for backfill entries. But the LRU-cap logic earlier says 'null announced_at goes last — those are unannounced dry-run entries and should not be re-alerted just because they were never notified.' If backfill entries get announced_at=today, they'll be evicted *first* under LRU pressure (oldest announced_at drops first), and once dropped they become eligible for re-alerting. Backfill should arguably use a distinct marker (e.g., backfilled_at) or null announced_at with a 'backfilled: true' flag, so they aren't both early-evicted AND re-alerted after eviction.
Recommendation
Either (a) keep backfilled forks pinned in seen-list (don't evict via LRU), or (b) add a 'backfilled: true' flag so eviction + re-alert logic can distinguish them from real announcements. Clarify intended semantics in the SKILL.md.