Fix clipboard fallback selection inside dialogs (#433)

test/ui/devices.test.js

@@ -380,8 +380,9 @@ describe('room: copy the invite without navigator.clipboard (LAN over http, iOS)
     const ta = {
       style: {}, value: '',
       setAttribute(k) { calls.push(['attr', k]); },
+      focus() { document.activeElement = ta; },
       select() { calls.push(['select']); },
-      setSelectionRange(a, b) { calls.push(['range', a, b]); },
+      setSelectionRange(a, b) { this.selectionStart = a; this.selectionEnd = b; calls.push(['range', a, b]); },
       remove() { calls.push(['remove']); },
     };
     const saved = { document: globalThis.document, secure: globalThis.isSecureContext, nav: Object.getOwnPropertyDescriptor(globalThis, 'navigator') };