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CloseAsync rethrew the graceful-shutdown exception after a successful Kill, so the manager faulted the session, recorded a CloseFailed fault and surfaced CloseFailed to the caller for the ordinary hung-worker case. docs/Sessions.md reserves CloseFailed for both shutdown and kill failing. A successful kill now completes the close as Closed; the shutdown failure rides back on SessionCloseResult.WorkerShutdownFailure and the manager logs it at warning level. Both-fail still raises CloseFailed.