Clean up Windows OAuth timeout

Committed-By-Agent: codex
Co-authored-by: codex <noreply@openai.com>

Author: lucasloisp

SDK/Runtime/EmbeddedWallet/WindowsWebViewHandler.cs

@@ -71,18 +71,25 @@ internal async static Task<OAuthResultData> RunOAuthFlow(string url, string redi
             var cancellation = Task.Delay(timeout);
 
             var completedTask = await Task.WhenAny(tcs.Task, cancellation);
+            var timedOut = completedTask == cancellation;
 
             // Only clear the shared reference if it still points at our tcs.
             lock (_oauthLock)
             {
                 if (_oauthTcs == tcs)
                 {
                     _oauthTcs = null;
+                    if (timedOut)
+                    {
+                        _oauthRedirectUri = null;
+                    }
                 }
             }
 
-            if (completedTask == cancellation)
+            if (timedOut)
             {
+                PrivyWebView_OAuth_HideWindow();
+                PrivyWebView_OAuth_SetRedirectUrl(null);
                 tcs.TrySetException(new TimeoutException("OAuth flow timed out."));
             }