GitHub
Also called Forge, GitLab, Hosting site
A website that hosts git repositories and adds what git lacks: pull requests, reviews, issues, permissions and automated checks on every push. Git is the tool. GitHub is one company's service built around it, and GitLab is another.
Everything on your machine can be skipped by whoever is at the keyboard, and that includes your agent. The server is where rules really hold: branch protection, required checks, required review. An agent with limited access can't talk its way past any of them.
Say it to your agent
“Using gh, add a ruleset for main: require a pull request, require the ci check to pass, and block force pushes and deletions. Then try a direct push to main and show me the refusal.”