refactor: organize desktop vs. mobile into separate folders

js/desktop/vite.preload.config.ts

@@ -0,0 +1,13 @@
+import path from "path";
+import { defineConfig } from 'vite';
+import { defineEnv } from './vite.env';
+
+// https://vitejs.dev/config
+export default defineConfig({
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
+  define: defineEnv,
+});