refactor(frontend): extract types, API, helpers, and preview from +page.svelte

frontend/vite.config.ts

@@ -5,6 +5,11 @@ import { sveltekit } from '@sveltejs/kit/vite';
 
 export default defineConfig({
 	plugins: [tailwindcss(), sveltekit()],
+	server: {
+      proxy: {
+        '/api': 'http://localhost:3000'
+      }
+    },
 	test: {
 		expect: { requireAssertions: true },
 		projects: [