v0.4.2

Added

• Comprehensive unit tests for QC module (tests/test_qc.py): 80 tests across 17 test classes covering get_eigen, estimate_s_rss, kriging_rss, compute_dentist_s, compare_maf, snp_missingness, ld_4th_moment, ld_decay, cochran_q, locus_qc, identify_outliers, remove_snps_from_locus, save_cleaned_locus, remove_outliers_and_rerun_qc, locus_qc_summary, qc_locus_cli, safe_qc_locus_cli, and loci_qc — achieving 82% coverage for credtools/qc.py

Changed

• Rewrote docs/qc.md to match actual code: tabbed quick-start examples, Python API example using exampledata, complete CLI parameter reference, QC method descriptions (Kriging RSS, Dentist-S, MAF comparison), accurate output directory structure and column tables, mermaid pipeline diagram, collapsible troubleshooting FAQ, and note that heterogeneity metrics are now in credtools meta