nx_bed_mesh_test.nx

nx_bed_mesh_test.nx -- verify bilinear interp + layer taper for slicer-side bed-mesh Z compensation. Closed-form invariants: (a) Flat bed (all deltas 0) -> z_offset returns 0 anywhere (b) set_point updates the right grid cell (c) Grid-corner queries return the exact stored value (d) Midpoint query returns the average of bracketing corners (e) Out-of-bounds queries clamp to nearest edge (no extrapolation) (f) Layer 0 returns full compensation (g) Layer == taper_layers returns 0 (h) Layer between linearly interpolates (1/2 taper -> 1/2 offset) (i) Bowl-shaped bed (corners 0, center +100μm) -> center query > 0 and edges == 0 (j) Bad indices return error verdict expect_exit: 0 license_tier: ORIGINAL