BD CuMesh Simplify

GPU-accelerated mesh simplification using CuMesh (CUDA). All operations are CUDA-accelerated: - target_faces → cu.simplify() edge collapse - remesh → cumesh.remeshing.remesh_narrow_band_dc() - preserve_sharp_edges_remesh → sharp edge preservation during remesh - fill_holes → cu.fill_holes() - remove_duplicate_faces → cu.remove_duplicate_faces() + cu.remove_degenerate_faces() - repair_non_manifold → cu.repair_non_manifold_edges() - remove_small_components → cu.remove_small_connected_components() Typical workflow for TRELLIS2 output: 1. Enable remesh + preserve_sharp_edges for cleaner topology 2. Enable mesh cleaning to fix topology issues 3. Target 5k-50k faces depending on use case 4. Use BD_BlenderDecimate with color_field for texture/color transfer Note: CuMesh operates on geometry only - vertex colors are NOT preserved.