nx_skullskin_gate.nx

nx_skullskin_gate.nx -- gate for the skull-bound tissue-depth skin (aesthetictwin AT46, 2026-09-18). ACCEPT RULE, PRE-DECLARED BEFORE THE FIRST RENDER (the coordinator's rule, with the two bars this lane could measure): (i) the photo ruler (nx_photomark_lib, the promoted ruler's own library, in-process) must FIND a face on the skin render with BOTH canthi of BOTH eyes (the baseline diora_fit_close.png reads UNMEASURED: no eye pair, measured 2026-09-18); (ii) the scale-free axes the ruler measures are PRINTED (canthal tilt per side, intercanthal_index, intercanthal_eq_fissure) and the intercanthal index must sit inside the canon band knowledge/facecanon.conf declares (intercanthal_index 380..420). The NME against knowledge/refintake/diora_baird.oracle is NOT measurable in-lane: the oracle carries rows for the reference stills only and a render gets an oracle row only from the outside oracle (MediaPipe on the laptop); (iii) the skin's midline profile extrema sit at the canon's thirds: the glabella-to-subnasale span equals the subnasale- to-menton span within the tissue-depth table's own spread (max voting depth minus min voting depth); (iv) no skin vertex penetrates the skull: the depth field is positive at every vertex; min/median/max are printed; (v) neg-control-zero-depth-field: every depth zero -> the skin equals the skull (max displacement 0); neg-control-doubled-cheek-fat: doubling one compartment moves ONLY vertices inside its 3-sigma support (partition printed and summed). Values are emitted with gv_kv/gv_check_eq/gv_check_near for independent adjudication. The arithmetic teeth run on a synthetic sphere fixture with PLANTED anchors (closed-form expectations computed here, not by the library); the anatomy teeth run on the real generated skull (a precondition: supplied as argv[1], else ./nx_skullsdf.elf is run from the estate root, ~130 s at 2 mm cells; absent -> those teeth SKIP, never acquit). Fixtures under /tmp/nx_skullskin_gate/. license_tier: ORIGINAL No hw writes (Rule 26).