HGVS Variant Converter (c. <-> g. <-> p.)

Parse an HGVS "c." variant description (by gene symbol, RefSeq NM_, or Ensembl ENST accession), convert it to genomic (g.) coordinates via a real, live-fetched Ensembl exon/CDS map (transcripts resolved through the bundled MANE RefSeq<->Ensembl crosswalk), apply 3'-rule normalization to any del/dup/ins, and predict the protein (p.) effect where that is safely computable. Also accepts a genomic "g." position on a chromosome or RefSeqGene (NC_/NG_, GRCh38 or GRCh37): it is validated and placed on GRCh38 by NCBI, projected onto the MANE Select transcript by Ensembl, and converted back by this tool's own engine, which must agree — so the answer rests on two independent conversions. And the "NC_/NG_(NM_…):c." form converts on the transcript in parentheses. A "c." on a RefSeq transcript outside MANE is placed by NCBI and converted on the gene's MANE Select transcript. A single amino-acid substitution ("TP53:p.Pro72Arg") is read as its codon change when exactly one single-base change produces it; otherwise every candidate is listed. Refuses cleanly — rather than guessing — for circular/mitochondrial genomes, RNA-level input, other protein-level input, uncertain/mosaic syntax, and splice-junction-adjacent or inversion protein effects.