A recovered detached daemon has no in-memory process handle, so two
concurrent refreshes can both enter settle for the same dead pid. The
initial guard runs before detached output is read; both continuations
could therefore pass it and then double-settle the generation.
Recheck generation and settled states after the awaited output read,
and cover concurrent refreshes against a recovered daemon. Without the
post-read guard the regression test observes restartCount 2 instead of
1.
Fixes#6852
roboomp
a0f353c561