On an address switch the background judges each tab by the origin of its URL. A page its server sandboxes has the origin "null" at a connected site's URL, and was sent the new active address. The background now names the origin it judged by on each accountsChanged event, and the content script passes the address on only when the page's own origin (window.origin) is that one; otherwise the page gets an empty list.
Model: opus-5-5