Function hunks_since 

pub async fn hunks_since(
    root: &Path,
    git_ref: &str,
    wanted: fn(&Path) -> bool,
) -> Result<Vec<Hunk>, GitError>

Hunks for what this branch changed relative to git_ref.

Three-dot (<ref>...HEAD), matching changed_since: the merge-base diff, so work that landed on the base branch after the fork is not attributed to this branch. CONTEXT_LINES of context is requested so the model has enough surrounding code to judge each change.