This particular things seems happening when i run these codes

AuthContext.jsx:

// context is a state management tool for passing props
import { createContext, useReducer } from "react";

// initial state
const initialState = {
  user: null, //user details
  role: null,
  token: null,
};
// create a common context with initial state
export const authContext = createContext(initialState);

// reducer function
const authReducer = (state, action) => {
  // action types
  switch (action.type) {
    case "LOGIN_START":
      // login starting
      return {
        user: null,
        role: null,
        token: null,
      };
    // login success
    case "LOGIN_SUCCESS":
      return {
        user: action.payload.user, //data will be recieved as a payload
        role: action.payload.role,
        token: action.payload.token,
      };
    // logout state
    case "LOGOUT": //data is set to null again
      return {
        user: null,
        role: null,
        token: null,
      };
    // default
    default:
      return state;
  }
};

// export provider
export const AuthContextProvider = ({ children }) => {
  //all children can access the provider
  const [state, dispatch] = useReducer(authReducer, initialState)
  return (
    <authContext.Provider
      value={{
        user: state.user,
        token: state.token,
        role: state.role,
        dispatch,
      }}
    >
      {children}
    </authContext.Provider>
  );
};

Login.jsx:

import { useState, useContext } from "react";
import avatar_img from "../assets/images/patient-avatar.png";
import { Link } from "react-router-dom";
import { useNavigate } from "react-router-dom";
import { toast } from "react-toastify";
import { authContext } from "../context/AuthContext.jsx";
export default function Login() {
  const [loading, setLoading] = useState(false);
  const navigate = useNavigate();
  const { dispatch } = useContext(authContext);
  const [formData, setFormData] = useState({
    // login function parameters
    email: "",
    password: "",
  });
  const handleChange = (e) => {
    setFormData({ ...formData, [e.target.name]: e.target.value });
  };
  const handleSubmit = async (e) => {
    e.preventDefault();
    setLoading(true);
    try {
      const res = await fetch("http://localhost:8000/api/v1/auth/login", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify(formData),
      });
      const result = await res.json();
      if (!res.ok) {
        throw new Error(result.message || "Something went wrong");
      }
      dispatch({
        type: "LOGIN_SUCCESS",
        payload: {
          user: result.data,
          token: result.token,
          role: result.role, //result is from the res.json()
        },
      });
      console.log(result,"login data");
      toast.success(result.message);
      setLoading(false);
      navigate("/");
    } catch (error) {
      toast.error("Registration failed");
      setLoading(false);
      console.log("Error in registration", error.message);
    }
  };
  return (
    <section className="p-3 lg:p-1">
      <div className="w-full max-w-[570px] mx-auto rounded-md shadow-xl p-3 md:p-10">
        <div className="flex justify-center gap-[20px] items-center">
          <img
            src={avatar_img}
            className="w-[40px] h-auto rounded-full"
            alt=""
          />
          <h2 className="text-3xl text-center font-semibold text-irisBlueColor">
            Login
          </h2>
        </div>
        {/* login form */}
        <form action="" className="py-4 md:py-0" onSubmit={handleSubmit}>
          <div className="mb-5">
            <input
              type="email"
              name="email"
              id="email"
              placeholder="[email protected]"
              className="placeholder:text-gray-400 w-full px-4 py-3 border-b border-solid border-teal-500 focus:outline-none focus:border-b-green-500 text-[15px] leading-7 cursor-text "
              value={formData.email} //setting the value as email
              onChange={handleChange}
              required
            />
          </div>
          <div className="mb-5">
            <input
              type="password"
              name="password"
              id="password"
              placeholder="**********"
              className="placeholder:text-gray-400 w-full px-4 py-3 border-b border-solid border-teal-500 focus:outline-none focus:border-b-green-500 text-[15px] leading-7 cursor-text "
              value={formData.password} //setting the value as email
              onChange={handleChange}
              required
            />
          </div>
          <div className="flex items-center justify-between">
            <button className="btn mt-0" type="submit">
              Login
            </button>
            {/* link for register */}
            <p className=" text-textColor text-center">
              Don't have an account ,
              <Link
                to="/register"
                className=" text-irisBlueColor hover:text-primaryColor"
              >
                create one
              </Link>
            </p>
          </div>
          {/* google auth */}
          <button className="w-full outline-teal-500 rounded-2xl mt-5 font-semibold bg-primaryColor text-white p-3">
            continue with google
          </button>
        </form>
      </div>
    </section>
  );
}

Header.jsx:

import logo from "../../assets/images/logo.png";
import userImg from "../../assets/images/avatar-icon.png";
import { useEffect, useRef, useContext } from "react";
import { CgMenuMotion } from "react-icons/cg";
import { NavLink, Link } from "react-router-dom";
import { authContext } from "../../context/AuthContext";

const navLinks = [
  { path: "/", display: "Home" },
  { path: "/doctors", display: "Find a Doctor" },
  { path: "/services", display: "Services" },
  { path: "/contact", display: "Contact" },
];

export default function Header() {
  const { user, role, token } = useContext(authContext);
  console.log(user); // Verify the user object here

  const headerRef = useRef(null);
  const menuRef = useRef(null);

  const handleStickyHeader = () => {
    window.addEventListener("scroll", () => {
      if (document.body.scrollTop > 80 || document.documentElement.scrollTop > 80) {
        headerRef.current.classList.add("sticky__header");
      } else {
        headerRef.current.classList.remove("sticky__header");
      }
    });
  };

  useEffect(() => {
    handleStickyHeader();
  }, []);

  const toggleMenu = () => {
    menuRef.current.classList.toggle("show__menu");
  };

  return (
    <header className="header flex items-center" ref={headerRef}>
      <div className="container">
        <div className="flex items-center justify-between">
          <div>
            <img src={logo} alt="MEDICARE logo" />
          </div>
          <div className="navigation" ref={menuRef} onClick={toggleMenu}>
            <ul className="menu flex items-center gap-[2.7rem]">
              {navLinks.map((link, index) => (
                <li key={index}>
                  <NavLink
                    to={link.path}
                    className={(navClass) =>
                      navClass.isActive
                        ? "text-primaryColor text-[16px] leading-7 font-[600]"
                        : "text-textColor text-[16px] leading-7 font-[500] hover:text-primaryColor"
                    }
                  >
                    {link.display}
                  </NavLink>
                </li>
              ))}
            </ul>
          </div>
          <div className="flex items-center gap-4">
            {token && user ? (
              <div>
                <Link to="/">
                  <figure className="w-[35px] h-[35px] rounded-full cursor-pointer">
                    <img src={userImg} alt="" className="w-full rounded-full" />
                  </figure>
                </Link>
                <h1>{user?.name}</h1>
              </div>
            ) : (
              <Link to="/login">
                <button className="bg-primaryColor py-2 px-7 items-center text-white font-[600] h-[44px] flex justify-center rounded-[50px]">
                  Login
                </button>
              </Link>
            )}
            <span className="md:hidden" onClick={toggleMenu}>
              <CgMenuMotion className="h-6 w-6 cursor-pointer" />
            </span>
          </div>
        </div>
      </div>
    </header>
  );
}

main.jsx:

import React from "react";
import ReactDOM from "react-dom/client";
import App from "./App.jsx";
import "./index.css";
import { BrowserRouter } from "react-router-dom";
import { ToastContainer } from "react-toastify";
import "react-toastify/dist/ReactToastify.css";
import { AuthContextProvider } from "./context/AuthContext.jsx";
ReactDOM.createRoot(document.getElementById("root")).render(
  <React.StrictMode>
    <BrowserRouter>
      <AuthContextProvider>
        <ToastContainer
          theme="dark"
          position="top-right"
          autoClose={300}
          closeOnClick
          pauseOnFocusLoss={false}
        />
        <App />
      </AuthContextProvider>
    </BrowserRouter>
  </React.StrictMode>
);

the problem is the code console logs role and token but it gives me user as undefined

here is the screen shot of it :
console output image for Header.jsx:

the role and token are accessible but the user is undefined in Header.jsx