Caps the iteration length (and the matching GT slice) when set, so CI
tiers can stay fast on multi-thousand-frame sequences like EuRoC MH_01
(3682 frames ≈ 3+ hours at 3-5s/frame). Also useful for eyeballing a
new adapter's first N frames before committing to a full run.
Three new harness tests cover truncation, explicit None, and over-large
limits. No change to existing adapters or downstream tests.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Yuzviak