refactor: use vite instead of CRA

frontend/vite.config.ts

@@ -0,0 +1,22 @@
+import { defineConfig, loadEnv } from 'vite';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig(({ mode }) => {
+  const env = loadEnv(mode, process.cwd(), '');
+  const port = Number(env.PORT || 5173);
+  const https = env.HTTPS === 'true';
+
+  return {
+    plugins: [react()],
+    server: {
+      port,
+      https,
+      strictPort: true,
+    },
+    test: {
+      globals: true,
+      environment: 'jsdom',
+      setupFiles: './vitest.setup.ts',
+    },
+  };
+});