Long whole-job solves ran silently, so there was no way to tell a slow engine from a hung one until the timeout fired. --progress hands each solve a JobProgressLog that prints [job/engine] lines for start, finish (or failure/timeout), every plate commit, and candidate evaluations throttled to one line per 2 s so parallel runs stay readable. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>