ReapPendingTargets counts targets that are still 'unreachable' but have
already accrued at least their configured reap-after duration — they
are due to be reaped (on an upcoming reaper tick, or held back by the
rate cap or an in-flight command). Surfaced so an over-threshold target
is visible before any tombstone.
ReapedTargetsinteger
ReapedTargets counts targets whose current health state is 'reaped'.