Index: frontend/src/utils/authSession.js
===================================================================
--- frontend/src/utils/authSession.js	(revision 194c01621e96510fb6f238b2098a64b3663ec780)
+++ frontend/src/utils/authSession.js	(revision 194c01621e96510fb6f238b2098a64b3663ec780)
@@ -0,0 +1,37 @@
+export const AUTH_TOKEN_KEY = "authToken";
+export const AUTH_USER_KEY = "authUser";
+
+function decodeJwtPayload(token) {
+  try {
+    const parts = token.split(".");
+    if (parts.length < 2) return null;
+    const base64 = parts[1].replace(/-/g, "+").replace(/_/g, "/");
+    const normalized = base64.padEnd(Math.ceil(base64.length / 4) * 4, "=");
+    const json = atob(normalized);
+    return JSON.parse(json);
+  } catch {
+    return null;
+  }
+}
+
+export function isTokenExpired(token) {
+  if (!token) return true;
+  const payload = decodeJwtPayload(token);
+  if (!payload || typeof payload.exp !== "number") return true;
+  return payload.exp * 1000 <= Date.now();
+}
+
+export function getAuthToken() {
+  return localStorage.getItem(AUTH_TOKEN_KEY);
+}
+
+export function clearAuthSession() {
+  localStorage.removeItem(AUTH_TOKEN_KEY);
+  localStorage.removeItem(AUTH_USER_KEY);
+}
+
+export function logoutAndRedirect(path = "/dashboard") {
+  clearAuthSession();
+  window.location.assign(path);
+}
+