Function apply_hwnd_iconic_changed 

pub fn apply_hwnd_iconic_changed(
    state: &mut State,
    hwnd: u64,
    iconic: bool,
) -> Vec<Event>

Phase B.9.1 — handle Command::ReportHwndIconicChanged. Updates state. No drift directly — operator can read steady state via --diag wrr (B.9.2) if they want to see who’s minimized.