fix: redirect to login on expired/missing JWT and 401 responses

decnet_web/src/App.tsx

@@ -9,15 +9,30 @@ import Attackers from './components/Attackers';
 import Config from './components/Config';
 import Bounty from './components/Bounty';
 
+function isTokenValid(token: string): boolean {
+  try {
+    const payload = JSON.parse(atob(token.split('.')[1].replace(/-/g, '+').replace(/_/g, '/')));
+    return typeof payload.exp === 'number' && payload.exp * 1000 > Date.now();
+  } catch {
+    return false;
+  }
+}
+
+function getValidToken(): string | null {
+  const stored = localStorage.getItem('token');
+  if (stored && isTokenValid(stored)) return stored;
+  if (stored) localStorage.removeItem('token');
+  return null;
+}
+
 function App() {
-  const [token, setToken] = useState<string | null>(localStorage.getItem('token'));
+  const [token, setToken] = useState<string | null>(getValidToken);
   const [searchQuery, setSearchQuery] = useState('');
 
   useEffect(() => {
-    const savedToken = localStorage.getItem('token');
+    const onAuthLogout = () => setToken(null);
-    if (savedToken) {
+    window.addEventListener('auth:logout', onAuthLogout);
-      setToken(savedToken);
+    return () => window.removeEventListener('auth:logout', onAuthLogout);
-    }
   }, []);
 
   const handleLogin = (newToken: string) => {

decnet_web/src/utils/api.ts

@@ -12,4 +12,15 @@ api.interceptors.request.use((config) => {
   return config;
 });
 
+api.interceptors.response.use(
+  (response) => response,
+  (error) => {
+    if (error.response?.status === 401) {
+      localStorage.removeItem('token');
+      window.dispatchEvent(new Event('auth:logout'));
+    }
+    return Promise.reject(error);
+  }
+);
+
 export default api;