PGx star alleles: pgx star-allele call (PGX-011..021), probe masks vs 1000G, GeT-RM validation (K-029)

- simurg/pgx/star.py: solver-free diplotype enumeration incl. CN forms (deletion, xN), wildcards, array-equivalence
  classes, raw_score/score with CPIC frequency priors; calibrated error model (spec PGX-012 amended).
- pipeline/pgx_star.py: DB gene models, SNV + PGx CN VCF evidence, masks, diplotype_summary.tsv + pgx_calls.json.
- scripts/pgx: derive_masks.py (array vs 1000G 30x over HTTPS, GS calibration), getrm_truth.py,
  validate_star_getrm.py.
- GSA v4 PGx demo vs GeT-RM (16 CEPH): 100/109 gene calls; CYP2D6/2C19/2C9 41/45 (docs/validation/V2_pgx_star.md).

scripts/pgx/build_cn_regions.py

@@ -49,12 +49,12 @@ def main() -> int:
     rows: list[tuple[str, int, int, str, str]] = []
 
     def exon(gene: str, k: int) -> tuple[int, int]:
-        chrom, strand, s, e = tx[gene]
+        _, strand, s, e = tx[gene]
         i = k - 1 if strand == "+" else len(s) - k
         return s[i], e[i]
 
     def intron(gene: str, k: int) -> tuple[int, int]:
-        chrom, strand, s, e = tx[gene]
+        strand = tx[gene][1]
         a_, b_ = exon(gene, k), exon(gene, k + 1)
         return (a_[1], b_[0]) if strand == "+" else (b_[1], a_[0])