Function git_clone_or_update 

pub fn git_clone_or_update(
    install_dir: &str,
    repo_url: &str,
    dry_run: bool,
) -> Result<(), String>

Clone a git repository or update it if it already exists.

If the directory exists and contains a .git folder, performs a fetch and hard reset. Otherwise, clones the repository.

Supports dry-run mode — logs commands without executing.