stage_hunks.py takes git diff -U0 of one file, keeps the added lines of an add-only hunk that match a regex and every other hunk whole when one of its changed lines matches, and applies the result to the index with git apply --cached --unidiff-zero --recount, or prints it with --dry-run; exit 1 when nothing matches. Step 4 of kvb-git-commit-next names it for a file that carries two bundles, which replaces the hand-written partial patches needed five times on 2026-11-03. tests/test_stage_hunks.py covers matching, the unstaged rest and the exit codes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
