Adapt the web backend for the rng selection.

TrimSP.html

@@ -4,8 +4,16 @@
   <meta http-equiv="Content-type" content="text/html;charset=UTF-8">
   <link rel="stylesheet" href="ZGUI.css">
   <link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
-  <script src="TrimSPelec.js"></script>
-  <!script src="TrimSPWeb.js"></script>
+  <script src="TrimSPweb.js"></script>
+  <script>
+    // Electron exposes CommonJS module support; plain browsers do not.
+    // Load the Electron-specific helpers only for the standalone app.
+    if (typeof module !== 'undefined' && module.exports) {
+      document.write('<script src="TrimSPelec.js"><\\/script>');
+    } else {
+      document.write('<script src="plotly.js"><\\/script>');
+    }
+  </script>
   <script src="TrimSPlib.js"></script>
   <script src="myplots.js"></script>
   <!script src="https://cdn.plot.ly/plotly-latest.min.js"></script>