Lock idempotency keys alongside row ids in TryAppend so concurrent
duplicate keys cannot both succeed; return true from TryClearInstance
when the row is absent to match Postgres idempotent DELETE behavior.
Replace .ToArray() with collection spread, simplify single-statement
await using blocks, use Lock for Postgres schema gates, and document
IDE0063/IDE0305/IDE0330/CA1859 conventions in csharp-style.md.
Durable per-player contract instances (one active) and append-only
outcome audit rows, mirroring NEO-116/135 store patterns with V011/V012
migrations, AAA tests, README docs, and Bruno health smoke.
VinPropane