Update TGBeta.ps1

TGBeta.ps1

@@ -865,6 +865,13 @@ function GetHtmlContent {
               });
         }
 
+        // Intercept window close or refresh
+        window.addEventListener('beforeunload', (event) => {
+            endSession(); // Clean up on window close
+            // Uncomment below for a confirmation dialog
+            event.returnValue = "Are you sure you want to leave?";
+        });
+
         function appendLog(message, color = "white") {
             const log = document.createElement('p');
             log.style.color = color;