Review round 1 on 4048e0f60 found two defects.
Startup recovery ran unconditionally. A continuation retry now refuses
while processing is halted, so a broker restart with a waiting
continuation failed with processing-halted. Startup recovery now waits
while processing is halted or invalid, as the periodic pass does;
processing.resume schedules it again.
#continuationStarting matched any launch without an end, so an older
launch whose end was lost (#1851) hid every later run's end. Only the
target's latest lifecycle event counts now.
Both regression tests fail on 4048e0f60 and pass here.
jason.woltje
c04529c7bb