Review of #172 (rule 9): "LeaksNothing" claims more than a 1.5s sampled race can prove -- the same overclaim this PR removes from the "Never" names. Renamed to DoesNotReturn...DuringASampledSwapRace, and the brainfstest doc now says the target may be inside the brain (#171) and that observation is over a sampled window. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>