Fast 3D Alpha Hull with Label Propagation // Fast 3D alpha shape (alpha hull) computation with label propagation from input points to hull vertices and faces. Uses 'CGAL' for robust geometric computations. Optimized for Light Detection and Ranging ('LiDAR') processing and tree segmentation workflows. The implementation follows the alpha shape algorithm described in Edelsbrunner et al. (1983) doi:10.1007/BF02579193.