The "probabilities are all non-negative" test was timing out intermittently
in CI (5s budget, 500 iterations × 48 teams). It's made redundant by the
"column sums ≈1.0" test immediately above it — any negative probability
would force a sibling value above 1.0, which toBeCloseTo(1.0, 2) catches.
Non-negative assertions for edge cases are also covered by the "SF losers"
test that follows.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
