split-stack
Installation
SKILL.md
Split Stack
Carves one or more concerns out of an existing PR into their own PRs, stacked on the original. The base PR keeps the concern the reviewer cares about first; each carved-out concern becomes a child PR based on the one below it.
The invariant that makes this safe: the top of the stack must be byte-identical to the original commit. Verify it, don't assume it.
Argument: a PR number or URL, plus which concern to split out.
Step 1 — Read the PR and classify every hunk
gh pr view <pr> --json number,title,body,headRefName,baseRefName,url
git fetch origin
git log --oneline <base>..<head>
git diff <base>...<head> --stat
git diff <base>...<head>
If the split isn't obvious from the PR body's checklist, ask which concern to extract — before reading the diff, so the classification has a target.