Merge a teammate's branch to keep credit, not copy files

To fold a teammate's open PR into your own branch while keeping their authorship, run git merge --no-ff --no-commit origin/their-branch, resolve conflicts, and commit the merge. Their commits stay in history under their name, and their PR auto-closes as merged once your branch lands in the base. Make any removals or rule fixes in separate follow-up commits rather than inside the merge. After merging, run make -n to catch new warnings such as 'overriding recipe for target': a directory they added can collide with an existing phony make target of the same name.