Function gutter 

pub fn gutter(
    endpoint: &RemoteEndpoint,
    workdir: &Path,
    head_sha: Option<&str>,
    rel: &Path,
    text: &str,
    cancel: &CancelToken,
) -> Result<(Vec<Hunk>, Vec<Hunk>, bool), RemoteGitError>

Fetch a file’s HEAD and index contents and assemble the gutter’s typed hunk sets against the live buffer text — the same semantics crate::Repo::unstaged_hunks/[staged_hunks]/[is_untracked] give local buffers, from bounded remote reads. Untracked files report one all-add hunk, matching local behavior.