P5T2 bug found during P5T5 Phase D smoke: walk-forward folds accumulated consecutive_warn/consecutive_error streaks across boundaries because reset_for_fold did not clear MetricBandsRegistry. F2 tripped termination at 6 consecutive even though no fold individually crossed 2N=6.
Fix: add MetricBandsRegistry::reset_streaks() that clears both HashMaps; called from DQNTrainer::reset_for_fold. New unit test reset_streaks_clears_consecutive_counters proves per-fold isolation. 9/9 monitoring unit tests pass. cargo check clean at 11 warnings.