Set turbopack.root to the monorepo root in next.config.mjs to resolve the Next.js Turbopack workspace root error.

apps/web/next.config.mjs

@@ -1,5 +1,10 @@
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
 import createNextIntlPlugin from "next-intl/plugin";
 
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+
 const withNextIntl = createNextIntlPlugin("./i18n/request.ts");
 
 /** @type {import('next').NextConfig} */
@@ -12,6 +17,10 @@ const nextConfig = {
   // IMPORTANT pour éviter les problèmes de paths en monorepo
   outputFileTracingRoot: process.cwd(),
 
+  turbopack: {
+    root: path.join(__dirname, "..", ".."),
+  },
+
   // optimise build (optionnel mais recommandé)
   poweredByHeader: false,
   compress: true,