✨ Make new frontend available under /modern

👷 Start adding deploy config and CI

frontend/src/App.tsx

@@ -10,9 +10,11 @@ import { Header } from "./components/Header";
 import { Toast } from "./components/Toast";
 import { ToastProvider } from "./components/ToastProvider";
 
+const baseUrl = import.meta.env.BASE_URL;
+
 const App: React.FC = () => (
   <ApolloProvider client={client}>
-    <Router>
+    <Router basename={baseUrl.replace("/static", "")}>
       <ToastProvider>
         <Header />
         <div className={styles.app}>