Cmd-Q went straight through to teardown, killing the backend mid-tool-call
— the turn is gone and whatever the agent was part-way through writing
stays part-way written, with nothing on screen to warn about it.
Renderers now report which chats are mid-turn; before-quit merges the
reports and asks, naming them, defaulting to Keep Running. Update, swap,
and uninstall relaunches skip the prompt: those are the app replacing
itself, and a modal there would strand the detached script waiting on a
PID that never exits.