Validate lockfile remains unchanged during copilot setup, add npm cac…#1560

nathanjmcdougall merged 3 commits intomainusethis-python/usethis-python:mainfrom

1559-validate-skills-lockfile-is-unchanged-in-copilot-setup-stepsusethis-python/usethis-python:1559-validate-skills-lockfile-is-unchanged-in-copilot-setup-stepsCopy head branch name to clipboard