feat: scaffold React frontend with login/register UI

frontend/vite.config.ts

@@ -0,0 +1,21 @@
+/// <reference types="vitest/config" />
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+
+export default defineConfig({
+  plugins: [react()],
+  build: {
+    outDir: 'dist',
+  },
+  server: {
+    proxy: {
+      '/auth': 'http://localhost:7777',
+      '/healthz': 'http://localhost:7777',
+    },
+  },
+  test: {
+    environment: 'jsdom',
+    globals: true,
+    setupFiles: './src/setupTests.ts',
+  },
+})