Fix: Stream-close-warning via IPC statt async executeJavaScript

- Renderer meldet Streaming-Status synchron per IPC
- main.js prueft Status synchron im close-Handler
- Kein async Race mehr, Dialog erscheint zuverlaessig

electron/main.js

@@ -106,25 +106,22 @@ function createWindow() {
     }
   });
 
+  // Track streaming status from renderer (synchronous — no async race)
+  let isStreaming = false;
+  ipcMain.on('streaming-status', (_event, active) => { isStreaming = active; });
+
   // Warn before closing if a stream is active
-  let forceClose = false;
   mainWindow.on('close', (event) => {
-    if (forceClose) return;
-    event.preventDefault();
-    mainWindow.webContents.executeJavaScript(
-      `Array.from(document.querySelectorAll('video')).some(v => v.srcObject?.active)`
-    ).then((isStreaming) => {
-      if (!isStreaming) { forceClose = true; mainWindow.close(); return; }
-      const result = dialog.showMessageBoxSync(mainWindow, {
-        type: 'warning',
-        buttons: ['Beenden', 'Abbrechen'],
-        defaultId: 1,
-        cancelId: 1,
-        title: 'Stream laeuft noch!',
-        message: 'Ein Stream ist noch aktiv.\nBeim Beenden wird der Stream gestoppt.',
-      });
-      if (result === 0) { forceClose = true; mainWindow.close(); }
-    }).catch(() => { forceClose = true; mainWindow.close(); });
+    if (!isStreaming) return;
+    const result = dialog.showMessageBoxSync(mainWindow, {
+      type: 'warning',
+      buttons: ['Beenden', 'Abbrechen'],
+      defaultId: 1,
+      cancelId: 1,
+      title: 'Stream laeuft noch!',
+      message: 'Ein Stream ist noch aktiv.\nBeim Beenden wird der Stream gestoppt.',
+    });
+    if (result !== 0) event.preventDefault();
   });
 }