The per-connection cancellation scope for this request. This is
the Mcp-Session-Id when stateful sessions are enabled, so a request and its
later notifications/cancelled -- which arrive on SEPARATE POSTs sharing only
that header -- resolve to the SAME RequestScope cancellation key. When
sessions are disabled there is no shared identifier across the two POSTs, so
the empty (shared) token is returned and bare-id cancellation is unscoped.
The per-connection cancellation scope for this request. This is the Mcp-Session-Id when stateful sessions are enabled, so a request and its later notifications/cancelled -- which arrive on SEPARATE POSTs sharing only that header -- resolve to the SAME RequestScope cancellation key. When sessions are disabled there is no shared identifier across the two POSTs, so the empty (shared) token is returned and bare-id cancellation is unscoped.