fix: give the `/` and `%` facts of cutsat the generation of `a`

`pushDivModFact` added the facts about `a / k` and `a % k` with generation 0, so their terms got generation 0 even when `a` came from E-matching.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2 files changed