nx_gltf_export_gate.nx

nx_gltf_export_gate.nx -- prove the glTF/.glb export (roadmap R7, VRM foundation): mesh the bestiary, write a binary glTF per variant, and validate the container: magic "glTF" + version 2 + total-length == filesize + a JSON chunk (POSITION/NORMAL accessors) + a BIN chunk big enough for the geometry the JSON declares. This is a REAL interchange format (three.js/Unity/Godot/Blender import it), the step up from STL/OBJ toward riggable VRM avatars. MIGRATED OFF D001 2026-08-26. This gate used to hand-roll a `fails` tally and print its own "GLTF-EXPORT-GATE 4/4 verdict=GREEN" line, so /api/promote refused it: nothing outside could read its outcome, nx_gate_green could not judge it, and it recorded no harness.jrnl frame, leaving flake and erosion invisible for it. It now inherits nx_gate_verdict -- per-tooth gv_check, so declared == executed by construction, and the verdict is carried in the EXIT CODE where /api/gate_run reads it. The migration surfaced two vacuity defects, fixed here rather than carried across: - the BIN-size check compared got_bin >= nv*24 + nf*12, which PASSES when the mesher returns nv=0 and nf=0. A tooth that passes on the empty set is not a tooth. The vertex and triangle counts are now declared SUBJECTS, so an empty mesh ends SKIP (no evidence) instead of scoring a silent GREEN. - the six-variant export loop printed a line per file and asserted NOTHING about any of them, so a write_glb returning 0 for every variant was invisible. It is a tooth now. Two neg-controls drive the header detector and the JSON scanner with crafted inputs, because a checker that answers the same way for everything scores 100% and proves nothing. license_tier: ORIGINAL No hw writes (Rule 26). expect_exit: 0