Cancelling ClientWebSocket.ReceiveAsync via CancellationToken ABORTS the
socket (a half-read WS frame can't resume). The per-iteration
iterationCts.CancelAfter(WebSocketReceiveTimeoutSeconds) therefore aborted a
healthy idle ARI WebSocket every 45s (state=Aborted), not the keepalive pong
(proven: loop persisted after pong-timeout 15s->3600s). A large receive
timeout lets ReceiveAsync block harmlessly while the PBX is idle; real drops
still surface immediately as WebSocketException -> reconnect. Proper code fix
(stop using CancelAfter on the receive) tracked separately.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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