initial commit

apps/web/app/routes/not-found.tsx

@@ -0,0 +1,21 @@
+/* ============================================================================
+   CATCH-ALL 404
+   ----------------------------------------------------------------------------
+   Owned by the app shell, not by a page agent.
+
+   Anything that matches no route lands here and throws, so the localised
+   "Page not found" screen lives in exactly one place: the root ErrorBoundary.
+   The locale still resolves correctly, because /ar/does-not-exist keeps its
+   prefix and `useLocale()` reads the pathname.
+   ========================================================================= */
+
+import { data } from "react-router";
+
+export function loader() {
+  throw data("Not Found", { status: 404, statusText: "Not Found" });
+}
+
+/** Never rendered - the loader always throws. */
+export default function NotFound() {
+  return null;
+}