Demanding a 10% gain to keep doubling settled [1,2]->1 on the first
noisy plateau (lbv2: 4k..2M-token docs, completion-rate noise dwarfs
10%). Now: keep climbing while not clearly worse (>=0.9x); bisect only
on clear degradation; samples per level doubled (max(3, 2*level)) to
shrink noise; steady re-probes +1 after ~60s so a noise-induced settle
cannot pin the gate forever. Overshoot past the true knee is trimmed
by the failure channel (timeouts -> x0.7), which is the real ceiling
finder on a prefill-bound endpoint.
Noise-swept at +-25%: capacities 4/8/16 settle at 11/31/16 without a
failure model; production failures pull the overshoot back down.
Co-Authored-By: Claude <noreply@anthropic.com>
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