Function update_stack_notes 

pub fn update_stack_notes(
    review_provider: &dyn ReviewProvider,
    branch_parents: &[(String, String)],
    dry_run: bool,
) -> Result<()>

Maintain a stack overview in every review body: the full ledger leaf-first, the trunk at the bottom, and a pointing emoji marking the review being viewed. Lives between marker comments so refreshes replace it in place, and self-repairs if the markers were hand-edited away. Merged and closed entries are preserved from the previous note and restyled instead of dropped.