nx_slice_bridge.nx

nx_slice_bridge.nx -- LIB: R1-FULL. The JOIN between the mature slice pipeline and the multi-material emitter. The slicer (nx_slice_plane -> nx_slice_contour) produces `NxPolygon` contours in Q14 fixed-point (1 unit = 1/16384 mm); this bridges an NxPolygon into the (xs,ys mm) contour `cp_emit_prism` consumes -- so ANY sliced 3D model prints in ANY material. The bridge is a pure Q14->mm conversion; no new geometry, no float, never-brick inherited. license_tier: ORIGINAL