Function run_git_raw 

pub fn run_git_raw(
    args: &[&str],
    cwd: &Path,
    context: &str,
) -> Result<Output, MarsError>

Run a git command and return the raw Output, allowing caller to handle exit codes.

Unlike run_git, this does not treat non-zero exit codes as errors. Use this for commands like git merge-file where positive exit codes have meaning.