feat(Save/Restore ui): add warning before exit and reload

src/pages/index.tsx

@@ -1,8 +1,12 @@
 import ParBar from '../components/ParametersBar';
 import ControlBar from '../components/ControlBar';
-import { DiffusionPlane, type SimulationParams } from '../components/Simulation';
+import {
+  DiffusionPlane,
+  type SimulationParams,
+} from '../components/Simulation';
 import { Canvas } from '@react-three/fiber';
 import styled from 'styled-components';
+import { useEffect } from 'react';
 
 const SimulatorContainer = styled.div`
   position: relative;
@@ -34,7 +38,17 @@ interface IndexProp {
 
 export default function Home(props: IndexProp): React.ReactElement {
   const { simulationParams, setSimulationParams, worker } = props;
-
+  useEffect(() => {
+    const confirmExit = (e: BeforeUnloadEvent) => {
+      console.log('beforeunload event triggered');
+      e.preventDefault();
+      e.returnValue = '';
+    };
+    window.addEventListener('beforeunload', confirmExit);
+    return () => {
+      window.removeEventListener('beforeunload', confirmExit);
+    };
+  }, []);
   return (
     <>
       <ParBar params={simulationParams} setParams={setSimulationParams} />