feat: add frontend as flat files (was submodule)

frontend/vite.config.js

@@ -0,0 +1,14 @@
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+
+export default defineConfig({
+  plugins: [react()],
+  server: {
+    host: '0.0.0.0',
+    port: 5173,
+  },
+  build: {
+    outDir: 'dist',
+    assetsInlineLimit: 0,
+  },
+})