fix(pwa): keep PWA alive during TG login (anchor opens Telegram, app polls on /tg-wait)

window.location.href=deep_link navigated the whole PWA to t.me, destroying the
/tg-wait polling screen -> the authenticated token was never fetched. Prefetch
the pairing session and open Telegram via an <a href> (OS app-switch, PWA stays
mounted polling); add an Open-Telegram fallback link on the wait screen.

Co-Authored-By: claude-flow <ruv@ruv.net>

driver-pwa/frontend/src/pages/TgWaitPage.tsx

@@ -6,6 +6,7 @@ import { Spinner } from "@/components/Spinner";
 export function TgWaitPage() {
   const nav = useNavigate();
   const pairSession = sessionStorage.getItem("pp-pair-session");
+  const deepLink = sessionStorage.getItem("pp-pair-deeplink");
   const { status } = usePairPoll(pairSession);
 
   useEffect(() => {
@@ -13,14 +14,29 @@ export function TgWaitPage() {
   }, [pairSession, nav]);
 
   useEffect(() => {
-    if (status === "authenticated") { sessionStorage.removeItem("pp-pair-session"); nav("/", { replace: true }); }
-    if (status === "expired") { sessionStorage.removeItem("pp-pair-session"); nav("/login", { replace: true, state: { expired: true } }); }
+    if (status === "authenticated") {
+      sessionStorage.removeItem("pp-pair-session");
+      sessionStorage.removeItem("pp-pair-deeplink");
+      nav("/", { replace: true });
+    }
+    if (status === "expired") {
+      sessionStorage.removeItem("pp-pair-session");
+      sessionStorage.removeItem("pp-pair-deeplink");
+      nav("/login", { replace: true, state: { expired: true } });
+    }
   }, [status, nav]);
 
   return (
     <div className="pt-16 text-center">
       <h1 className="text-xl font-extrabold mb-2">Премиум Водитель</h1>
-      <p className="text-muted text-sm mb-8">Подтвердите номер в Telegram — нажмите «Поделиться номером», затем вернитесь сюда.</p>
+      <p className="text-muted text-sm mb-6">
+        В Telegram нажмите «Поделиться номером для входа», затем вернитесь сюда — вход произойдёт автоматически.
+      </p>
+      {deepLink && (
+        <a href={deepLink} target="_blank" rel="noopener noreferrer" className="btn-primary block text-center mb-6">
+          Открыть Telegram
+        </a>
+      )}
       <Spinner />
     </div>
   );