update webapp + bonsai integration

src/ifctester/webapp/svelte.config.js

@@ -0,0 +1,7 @@
+import { vitePreprocess } from '@sveltejs/vite-plugin-svelte'
+
+export default {
+  // Consult https://svelte.dev/docs#compile-time-svelte-preprocess
+  // for more information about preprocessors
+  preprocess: vitePreprocess(),
+}