Function ancestor_royalty 

pub fn ancestor_royalty(
    total_royalty: u64,
    generation: u32,
    share_percent: u64,
) -> u64

The royalty owed to an ancestor generation levels up a derivation chain: a geometric split where each level takes share_percent of what reaches it — total × (share_percent/100)^(generation+1). Generation 0 = the immediate parent. Saturating integer arithmetic; zero-heap. (Recursive commons attribution for derivative works.)