Automatically configure default preload URL if the backend serves the frontend directly.

Fixes #207

vite.config.ts

@@ -5,6 +5,7 @@ import vue from '@vitejs/plugin-vue'
 import vueJsx from '@vitejs/plugin-vue-jsx'
 import {name, version} from './package.json'
 import {execSync} from 'child_process'
+import topLevelAwait from "vite-plugin-top-level-await";
 
 // https://vitejs.dev/config/
 export default defineConfig({
@@ -18,6 +19,12 @@ export default defineConfig({
             }
         }),
         vueJsx(),
+        topLevelAwait({
+            // The export name of top-level await promise for each chunk module
+            promiseExportName: "__tla",
+            // The function to generate import names of top-level await promise in each chunk module
+            promiseImportName: i => `__tla_${i}`
+        }),
     ],
     resolve: {
         alias: {