Fix session persistence after logout - clear localStorage

web/static/js/app.js

@@ -61,7 +61,7 @@ document.getElementById('loginForm').addEventListener('submit', async (e) => {
 
 // Logout
 document.getElementById('logoutBtn').addEventListener('click', () => {
-    sessionId = null;
+    localStorage.removeItem('session_id');
     location.reload();
 });