A stream-json Claude CLI stub asks one AskUserQuestion and then follows a
scripted row (interrupt, stop, transport failure, provider withdrawal with a
replacement question, normal answer, stale cancel after answering). The
driver runs a real server against an isolated home and records persisted
events, the subscribeThread stream and the stub's wire trace per row.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>