Shutdown says what went wrong

When a mesh shuts down, the code that waits for it to finish used to convert the wait into a one-shot handle that could only ever report one thing. Anything that went wrong after that handle had already settled — a hub whose teardown failed a moment later, a background job that faulted on its way to idle — reached nobody at all: no log line, no error, nothing to search for afterwards.

Every one of those waits now stays subscribed for as long as the shutdown can still say something, so a late failure is written to the log with the address it came from. The shutdown report also carries two facts it previously threw away: whether the shutdown itself faulted, and whether running activities actually finished before the mesh was torn down.

Nothing about a healthy shutdown changes. What changes is that an unhealthy one is now visible instead of looking identical to a clean one.