fn popups_note(popups: Option<&Value>) -> StringExpand description
The snapshot’s lines about new windows the page opened: popup windows
(kind: "window", a native window, id popup-…) and popup panes (a
browser pane beside it). Empty when there are none. Each address is
quoted: the page chose it (SPEC_BROWSER_PANE_POPUPS_ADOPTED_2026_10_08.md
§3.4, SPEC_BROWSER_PANE_NATIVE_POPUPS_AGENT_DRIVEN_2026_10_08.md §5).