OFI trajectory (online LinReg), realized variance, Hawkes intensity, book pressure gradient, spread dynamics, aggression ratio, queue depletion, order count flux, intra-bar momentum (Welford), regime score, OFI acceleration, toxicity gradient. ExtendedOFIFeatures [20]. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>