Add frontend config and API client

frontend/vite.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+
+export default defineConfig({
+  plugins: [react()],
+  // Le build est embarqué dans le binaire Go (web/dist).
+  build: { outDir: "../web/dist", emptyOutDir: true, chunkSizeWarningLimit: 4096 },
+  // `npm run dev` : l'API Go tourne sur :8080.
+  server: { proxy: { "/api": "http://localhost:8080" } },
+  define: { "process.env.IS_PREACT": JSON.stringify("false") },
+});