Branching off origin/main set the new branch's upstream to origin/main, so a bare `git push` failed with a name-mismatch and suggested the dangerous `git push origin HEAD:main`. Add --no-track so the branch carries no upstream until the first `git push -u origin <branch>` sets the right one — keeping the fresh-from-origin/main base without the tracking side-effect. Add a test-wt.sh assertion that a new branch has no upstream, and note the behaviour + first-push form in ADR-0059 / CLAUDE.md.