More converting to typescript

frontend/vite.config.ts

@@ -0,0 +1,21 @@
+// frontend/vite.config.ts
+
+import tailwindcss from '@tailwindcss/vite';
+import react from '@vitejs/plugin-react';
+import path from 'path';
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  plugins: [react(), tailwindcss()],
+  test: {
+    globals: true,
+    environment: 'jsdom',
+    setupFiles: './vitest.setup.ts',
+    css: true,
+  },
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src'),
+    },
+  },
+});