nx_preflight_test.nx

nx_preflight_test.nx -- exercise preflight orchestrator with good + bad inputs across every failure class. Closed-form invariants: (a) Tetrahedron + Qidi X-Max 3 + Generic PLA + sane params -> SAFE. (b) n_checks_run == 4; n_failed == 0 on the safe case. (c) Non-manifold (3-tri mesh, removed one) -> UNSAFE / NOT_MANIFOLD. (d) Mesh 500mm cube (exceeds 325mm Qidi build) -> UNSAFE / MESH_TOO_LARGE. (e) Material with bad temp (mutate PLA to print 260°C) -> UNSAFE / BAD_THERMAL. (f) Slicer max_speed 1000 mm/s (Qidi max 600) at 0.4×0.2 line -> flow = 0.4 × 0.2 × 1000 = 80 mm³/s > machine 35 mm³/s -> UNSAFE / FLOW_EXCEEDED_MACHINE. (g) Slicer max_speed 200 at 0.4×0.2 -> flow 16 mm³/s; material max 15 -> UNSAFE / FLOW_EXCEEDED_MATERIAL. (h) Verdict name lookup non-NULL for every reason. expect_exit: 0 license_tier: ORIGINAL