[INFO] Reading target VCF: Sig_18_Blood.chip.harmonized.vcf.gz
[INFO] Reading source VCF: Sig_18_Blood.germline.harmonized.vcf.gz
[INFO] Adding header fields with prefix 'GERMLINE' for: GT, AD, DP, GQ, QD
[INFO] Building source variant lookup...
[INFO] Found 395 variants in source VCF
[INFO] Processing target variants and merging characteristics...
[INFO] Complete! Processed 321 variants, matched 34 (10.6%)
[SUCCESS] VCF merging completed successfully!