Get variant information from any LD reference source.
Source:R/file_utils.R
get_ref_variant_info.RdAuto-detects the source type (PLINK2, PLINK1, VCF, GDS, or pre-computed LD metadata) and returns variant metadata. For PLINK2, opens only the .pvar file. For PLINK1, reads only the .bim file. For VCF and GDS, loads the full file and extracts variant info.