v1.3.1

This version fixes a TWAS sign swap bug introduced in v1.0.4 (2025-03-02).

plink2R had been replaced with snpStats to avoid manual install step. But snpStats loads genotype dosages in terms of A2 allele rather than the A1 allele as plink does. This led to top1 and enet model types having flipped weights since they used the loaded genotypes, while the other model types were computed via subcommands. TWAS associations and phenotype predictions based on the models had flipped signs. Now, loaded dosages are subtracted from 2 to flip back to the A1-based representation expected by downstream applications.