Quorum
Fans out one finder agent per file, then sends each finding through K=3 skeptic agents that independently try to kill it, routing each task to the cheapest model that can handle it.
K=3 verification cut false positives from 27.8% to 0.0% (95% CI [11.1, 50.0] to [0, 0]). That came with a real trade-off, recall dropped from 100% to 77.8%. On a held-out real target it found 3/3 genuine bugs with zero surviving false positives, at about $0.25 per run. 58 tests, CI green.
Quorum routes each task across tiers (DeepSeek, Haiku, Sonnet, Opus). The harness is committed and tested, but the live multi-tier cost number is gated on an operator key, so I am not publishing one rather than fabricate it.