snapshot() ignored settle()'s result, so on a loaded machine (seen on the FreeBSD VM and
under local load) a timed-out settle compared half-rendered frames and failed as a
misleading pixel diff. The test now settles explicitly with a 300 s budget, asserts it
settled, then paints.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>