nx_csg_scene_gate.nx

nx_csg_scene_gate.nx -- GATE for the N-primitive CSG scene extractor (nx_csg_scene). Proves a MULTI-feature solid -- a block MINUS two through-holes UNION a riser (4 prims, mixing DIFF and UNION) -- composes into ONE watertight, printable mesh, beyond what the 2-primitive nx_csg_extract can express. T1 the scene meshes: non-empty + nx_mesh_validate OK (indices in range). T2 WATERTIGHT + features: a mid-slice has n_open=0 AND >=3 closed loops (outer + 2 holes). T3 features present by inside-count: holes REMOVED material, riser ADDED material. T4 STL round-trip: write -> nx_stl_load_binary verdict OK, header tri count matches. T5 NEVER-BRICK (#26): pure-integer field + mesh + write; zero hardware-state writes. T6 LIAR-KILL: displacing a hole far outside the block restores material (field really depends on the primitive params -- the multi-feature result is not rigged). expect_exit: 0 license_tier: ORIGINAL