Modernize

Modernize the idea, not just the branch. A clean rebase does not prove that the PR still belongs in the product.

Guardrails

• Always check to make sure you have pulled latest origin for your branch, main branch, and any other branch related to your work before starting.
• Treat existing worktree changes as user-owned. Use a disposable worktree when the active worktree is dirty or is being used for other work.
• Modernizing authorizes rebasing and updating the PR branch. It does not authorize merging, closing, changing the base branch, or expanding scope.
• Never use an unqualified force push. Update a rebased branch with --force-with-lease against the head SHA observed before the rebase.
• Do not post a PR comment unless the user asked for one. Use the leaving-pr-comments skill for every comment posted on the user's behalf.

Establish the PR's intent

Resolve the PR and record its URL, state, base, head repository and branch, current head SHA, author, checks, and review state. Read the title, body, linked issues, commits, review threads, and complete diff. State the smallest coherent goal the PR was trying to accomplish before judging its implementation.

Fetch the latest remote base and PR head. Use the PR's actual base branch, usually main, rather than assuming the local branch is current. Record the merge base so the original PR and subsequent base-branch changes can be compared separately.

Check what changed around it

Inspect commits and diffs added to the base branch since the PR diverged. Search merged and open PRs when titles, code paths, or behavior suggest a replacement or competing implementation.

Look beyond overlapping lines: