Function updateUser

app/src/App.jsx:476–487

(idx, key, value)

  const removeUser = (idx) => setUsers(users.filter((_, i) => i !== idx));
  
  const updateUser = (idx, key, value) => {
    const newUsers = [...users];
    newUsers[idx] = { ...newUsers[idx] };

    if (key.includes('.')) {
      const [p, c] = key.split('.');
      newUsers[idx][p] = { ...newUsers[idx][p], [c]: value };
    } else {
      newUsers[idx][key] = value;
    }
    setUsers(newUsers);
  };

  const addSubItem = (userIdx, field, item) => {
    const newUsers = [...users];