remove hardcoded user id from home

public/js/home.js

@@ -67,8 +67,8 @@ document.addEventListener('DOMContentLoaded', () => {
         const response = await fetch('/api/plans', {
             method: 'POST',
             headers: { 'Content-Type': 'application/json' },
+            credentials: 'same-origin',
             body: JSON.stringify({
-                userId: 0,
                 textId: textId,
                 name: planName,
                 dateStart: dateStart,