master already stabilized the raw-mode SIGINT scenario in 65e0ffe03 and
3be090f1d with wider scenario-owned bounds and deliberately delayed child
readiness, so the merge takes master's test implementation. What this branch
keeps is the contract that explains why those bounds are required: the note
paragraph on the settle boundary in PtySendOperation.append, and the
waitForOutput comment recording that raising its deadline alone cannot
recover output the send never collected.
Chinesezjc
1927d347cd