Function commits_in_range 

async fn commits_in_range(
    cwd: &Path,
    base: &str,
    head: &str,
    budget: Duration,
) -> Option<Vec<GitCommit>>

The branch’s commit chain ahead of base, newest first, capped at COMMITS_WALK_CAP: the count says how many there are, these say what they are, and each carries the files it changed. Two walks of the same range - --numstat for the counts, --name-status for the marks, which git will not emit together. %h is the short sha, %s the subject; the unit separator cannot occur in either, so one line splits cleanly.