Function update_stack_notes 

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

Maintain a stack overview in every review body, one independent stack at a time: a PR’s overview must list only its own stack, never sibling stacks that merely share the trunk. branch_parents can span several such stacks (e.g. a sync run from the trunk), so group by each branch’s child-of-trunk root and refresh each group’s notes on its own.