Owner follow-up to the softphone (spec 05 §5). - the incoming call notification comes from a service worker (public/sw.js) so it carries Answer and Decline buttons (Chromium); Answer and a plain click focus the softphone tab, Decline doesn't - shown whenever the tab isn't focused, not only when it's hidden; kept up while it rings and closed once it stops - the softphone panel says how to allow notifications when they're blocked