feat: migrate legacy playout workflow and scenes

MainWindow.xaml.cs

@@ -130,6 +130,7 @@ public sealed partial class MainWindow : Window
         if (PlayoutBridgeProtocol.IsTrustedSource(uri.AbsoluteUri, AppHost) ||
             uri.Scheme == "about")
         {
+            QuarantineIfBrowserCorrelationCanBeLost();
             LoadingOverlay.Visibility = Visibility.Visible;
             return;
         }
@@ -192,6 +193,9 @@ public sealed partial class MainWindow : Window
                 case "playout-command":
                     _ = HandlePlayoutCommandAsync(request.Payload);
                     break;
+                case "playout-timeout-quarantine":
+                    _ = HandlePlayoutTimeoutQuarantineAsync(request.Payload);
+                    break;
                 case "request-market-data" when request.Payload.ValueKind == JsonValueKind.Object:
                     _ = HandleMarketDataRequestAsync(request.Payload);
                     break;
@@ -203,7 +207,7 @@ public sealed partial class MainWindow : Window
                     }
                     break;
                 case "reload":
-                    Browser.Reload();
+                    ReloadBrowserSafely();
                     break;
             }
         }
@@ -477,6 +481,7 @@ public sealed partial class MainWindow : Window
 
     private void OnProcessFailed(object? sender, CoreWebView2ProcessFailedEventArgs args)
     {
+        QuarantineIfBrowserCorrelationCanBeLost();
         ShowError("WebView2 프로세스가 종료되었습니다.", args.ProcessFailedKind.ToString());
     }
 
@@ -508,7 +513,23 @@ public sealed partial class MainWindow : Window
     {
         if (_webViewReady)
         {
-            Browser.Reload();
+            ReloadBrowserSafely();
+        }
+    }
+
+    private void ReloadBrowserSafely()
+    {
+        QuarantineIfBrowserCorrelationCanBeLost();
+        Browser.Reload();
+    }
+
+    private void QuarantineIfBrowserCorrelationCanBeLost()
+    {
+        if (Volatile.Read(ref _playoutCommandInFlight) != 0)
+        {
+            // Navigation or a renderer failure destroys the JavaScript request
+            // correlation. Latch native OutcomeUnknown before the document can go away.
+            _ = QuarantineForBrowserCorrelationLossAsync();
         }
     }