bayes for days

feat(candidates): record why each absent position fired nothing master

`TargetExchanges` kept the reasons only summed, so a sweep could not say what any one position contributed and nothing could be carried into the next rebuild. One byte per position, packed from the two blocked halves. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Change-Id: I2db96109478bd31eb92fa9647909e91924456d64


Author permadeath.com Co-author Claude Opus 5 (1M context) Committer Tangled Date Commit a935f179 Parent 39261496 Change ID I2db9610
+821
2 changed files