HttpStreamContext.isCancelled

Cancellation for this request. On released protocol versions (2025-03-26 / 2025-06-18 / 2025-11-25) cancellation is tracked solely by the server's RequestScope (the shared token flipped by `notifications/ cancelled`), so the transport context itself reports never-cancelled. On the draft Streamable HTTP transport a client disconnect IS the cancellation signal (draft basic/utilities/cancellation §Transport-Specific Cancellation: "The server MUST treat a client disconnect as cancellation of that request"), so a dropped connection reports cancelled and the wrapping RequestScope.isCancelled surfaces it to a polling handler.

class HttpStreamContext
@safe
bool
isCancelled
()