Complete Git and GitHub CLI repository management skill. Use when initializing git repos (git init), generating .gitignore files, creating GitHub repositories, cloning, editing, forking, listing, archiving, syncing, or managing repositories. Also handles GitHub CLI authentication (gh auth login, logout, status, token, refresh). Covers the full workflow from local project initialization to GitHub deployment. Includes git init, .gitignore templates for all major languages/frameworks, gh repo create (with all flags), gh repo edit, clone, fork, list, view, delete, archive/unarchive, sync, rename, deploy-key, and set-default commands.