Quitting a cloud session makes one last send attempt and prints anything undelivered.
What's wrong with this entry?
On exit, held messages get one final flush attempt with a 100ms retry budget, and anything that still did not make it is printed as a summary rather than vanishing silently.
- Undelivered messages read "not sent: the cloud session had not yet received this machine's files or settings when you quit."
- The summary also lists per-reason refusals and messages whose delivery was never confirmed, and is worded for one or several ("Your last message" / "Your last N messages").
- Reachable in any terminal-attached cloud session.
not sent: the cloud session had not yet received this machine's files or settings when you quit.
Strings lifted out of the shipped bundle, so the claim above can be checked against them.