All previously-derived parametric LUT forms (u563a60 A=-13.78/68.29/0.344, lut5/
lut4 gamma-LUT, power-law, linear 0.483/0.717, real extracted points) tested on the
full 59-case honest 24-bit metric within one fixed bridge pipeline. None beat the
committed Pchip (0.773; worst powerlaw 6.8). F1 closed: parametric curve production
was already done, none accepted; structural A/B/gamma from ctx+0x188 remains the only
path to bytes (blocked on level-path object live capture).