Start work on general workflow.

frontend/src/App.jsx

@@ -8,6 +8,38 @@ import './App.css';
 import 'bootstrap/dist/css/bootstrap.min.css';
 
 function App() {
+    // Ensure we have persistent (informal) user information
+    const [user, setUser] = useState("");
+    useEffect(() => {
+	localStorage.setItem('user', user);
+    }, [user]);
+    useEffect(() => {
+	const user = localStorage.getItem('user');
+	if (user) {
+	    setUser(user);
+	}
+    }, []);
+
+    // If no user, must be scanned/set otherwise
+    return (
+	<Container>
+	    {user === "" ?
+	     <NoUserView setUser={setUser} />
+	     :
+	     <UserView user={user} />}
+	</Container>
+    );
+}
+
+function NoUserView({setUser}) {
+    return <p>No user!</p>;
+}
+
+function UserView({user}) {
+    return <p>User={user}</p>;
+}
+
+function BarItemScanner() {
     const [reqAccount, setReqAccount] = useState('');
     const [actAccount, setActAccount] = useState('');
     const [balance, setBalance] = useState(-1);