fastnntr - Fast Rust-Based SplitsTree NeighbourNet Algorithm

A fast Rust implementation of the NeighbourNet algorithm (Bryant & Moulton, 2004) for phylogenetic analysis. It constructs an implicit split network from a distance matrix and returns it in a 'networx'-compatible structure for exploratory visualisation with 'tanggle', 'ggplot2', or 'phangorn'.