Temporary summon lifetime checks collide with their retained unique row #469

A current-main Binding quest durable run exposed a panic in expire_eventai_summon. Its replacement INSERT collides with the existing unique creature_guid in game_creature_ai_summon_expiry.

Evidence: CI run 34154396306, from report-only PR #467 on main 88c93ae. The uploaded Standalone log records DatastoreInsertBsatn errno 12 at 19:10:22 UTC and names expire_eventai_summon in the Wasm backtrace. The reducer inserts a new scheduled row without removing the current one.

The same run times out waiting for a dead Binding summon. Temporary-summon expiry can remove the dead entity before that poll observes it. The quest fixture should verify durable kill credit and accept normal corpse removal.

Done when an owned Standalone test proves a living summon survives repeated lifetime checks with one stable life number, expires after its allowed lifetime, and does not panic. A delayed obsolete callback must not alter a replacement summon. Keep the Binding quest's combat and exact kill-credit checks meaningful.

Codex owns the isolated diagnosis and fix. No existing Realm was accessed.