PGx: PharmVar genes (CYP1A2, CYP2A6, CYP2A13, CYP2C8, CYP3A4), CYP2A6 *4 from CN (PGX-001/006)

fetch_sources.sh downloads PharmVar per-gene zips; pgx db build adds core alleles for genes CPIC does not
define (normalised against the FASTA, *1 = reference). Masks re-derived with the new variants. GeT-RM:
CYP3A4 15/15, CYP2A6 7/9; all comparable genes 154/168 (CYP1A2/CYP2C8 definitions differ from GeT-RM's).

tests/unit/test_pgx_db.py

@@ -147,3 +147,12 @@ def test_coverage_statuses(tmp_path: Path) -> None:  # PGX-009 / PGX-035
     st = {r["allele"]: r["status"] for r in coverage_rows(db, "M")}
     assert st["*1"] == "callable" and st["*2"] == "callable"
     assert st["*3"] == "masked" and st["*5"] == "not_covered"
+
+
+def test_pharmvar_core_alleles() -> None:  # PGX-001 PharmVar source
+    from simurg.pgx.db import pharmvar_core_alleles
+
+    vcf = "##fileformat=VCFv4.1\n#CHROM\tPOS\tID\tREF\tALT\tQUAL\tFILTER\tINFO\nchr19\t100\trs1\tA\tC\t.\t.\t.\n"
+    core = pharmvar_core_alleles("CYP2A6", {"CYP2A6-6.2/GRCh38/CYP2A6_9.vcf": vcf,
+                                            "CYP2A6-6.2/GRCh38/CYP2A6_9.001.vcf": vcf})  # fmt: skip
+    assert core == {"*9": [("chr19", 100, "A", "C", "rs1")]}  # sub-alleles (*9.001) are not core definitions