Use the package's own `SubprocessTerminalActivity['state']` instead of a derived
alias, label the samples as `state:revision` so a reader cannot mistake the
suffix for a count, name the summariser's bound as a group count, and state only
the two observables the prompt count supports.
Refs #5755
An activity poll that times out reports only "unknown" or "Matcher did not
succeed in time". The Linux standby has failed that way twice, at different
polls, and the log shows nothing about what `inspect()` read, which returns
`unknown` for several distinct conditions.
Every activity poll now records the state and revision it samples and counts the
prompts printed while it waits, so a timeout names both. Repeated samples
collapse and the printed list is bounded. Timeouts, intervals and expectations
are unchanged, and where the poll budget equals the test budget the test timer
can still preempt this message.
Refs #5755
turtle1999