Twenty connections in turn: the client sends a request, and the server
answers 64 KiB with SendAsync(finish = true), destroys the stream
wrapper and deletes its ClientQUIC at once, as a server shutting down
does. Each answer must arrive whole with a clean end, and each delete
must stay well under the 1 s bound. Before the fix every answer was
reset.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
