The reminder count was one counter per lead per source, carried forward
across ticks. A counter carried forward has no memory of which item it
counted, so work arriving during the backoff window inherited an
already-capped count and was never named in a nudge.
tick() now recomputes each source's count fresh from the minimum count
among the items actually pending, tracked per item. A fresh item keeps
its source eligible; an older capped item still rides along in the text
without spending more budget. decide() is unchanged.
Verified here: read the diff; the bumped set is exactly the set named in
the nudge, and the empty early-return skips the bump. Trial merge onto
main builds 826 tests BUILD SUCCESS, unpiped.
Closes#87
Dai Ha
7a120b3256