Multi-Resolution Thin-Plate Splines on the Sphere // Constructs multi-resolution thin-plate spline basis functions on the sphere for use in spatial regression and large-scale spatial prediction problems. Implements the basis system described in Huang, Huang, and Ing (2025) "Multi-Resolution Spatial Methods on the Sphere: Efficient Prediction for Global Data", Environmetrics, doi:10.1002/env.70092. Heavy computations are written in 'C++' via 'Rcpp' with optional 'OpenMP' parallelism.