nx_twintruth_gate.nx

nx_twintruth_gate.nx -- the referee for the eye unit's landmark truth in nx_twinfit_lib (aesthetictwin AT39, 2026-09-17; split out of nx_twinfit_gate 2026-09-18). The projection is held to the renderer's own ray set-up; the canon face has truth on both eyes, mirrored about the frame centre, tilted as the canon gene says and confirmed on the surface inside the corner window; the eye genes leave the canon untouched, move the truth with the tilt gene and break the mirror with the difference gene; a face without lid shells has no truth and says why by name; seed 42 keeps its identity and its eye genes; the judge scores a planted ruler against planted truth. WHY A GATE OF ITS OWN: the truth scans march the surface at a fixed two-unit step because the lid-shell field is steep and discontinuous at the canthus (a distance-stepped march could skip the thin lid), so these teeth cost more than the rest of the twin loop together -- measured 13.3 s of a 22.8 s laptop run, 178 s on the NAS against the roster's 180 s per-gate deadline. One subject per gate lets each fit the roster. AT44 (2026-09-18) adds the MOUTH's truth and judge, which cost a few surface marches and no render (17 ms on the laptop): the lip judge exact on a planted case with a decoy in the stated-ratio slot, and the canon face's five lip points in anatomical order, the stomion on the lip sweep's front (the seam is seen at its opening, not its slit floor) and the vermilion lines on the marched surface. Values are printed with gv_kv. license_tier: ORIGINAL No hw writes (Rule 26).