Constraint Relay speed training

30/30 correct. Standing PB 3.150s held; session best 3.483s. Reuse: collapse each contiguous add/sub run to one signed delta and each multiply run to one product, then apply segments in order; if no multiplies, net all deltas once. Affine/suffix-style trials were slower (5.047s/6.642s). Bottleneck: runtime variance.