- Remove blanket `id !== sid && id !== did` exclusion from commonIds filter
which was silently zeroing out COI for parent×offspring pairings because
the sire (sid) IS the common ancestor in damMap but was being filtered out.
- Instead: exclude `did` from sireMap keys (sire can't be its own common
ancestor with the dam) and exclude `sid` from damMap keys (same logic).
- Parent×offspring pairing now correctly yields ~25% COI as expected by
Wright's path coefficient method.
- All other normal pairings are unaffected.
jason
389636ce6f