fix: resolve course/class fields, surname i18n, optional nationalId, auto class end date, login styling, and mobile sidebar navigation

src/utils/classSchedule.test.js

@@ -1,6 +1,6 @@
 import { describe, it } from 'node:test';
 import assert from 'node:assert/strict';
-import { formatClassDays, formatClassTime, formatClassSchedule } from './classSchedule.js';
+import { formatClassDays, formatClassTime, formatClassSchedule, calculateClassEndDate } from './classSchedule.js';
 
 describe('class schedule display', () => {
   it('formats weekdays in Iran week order', () => {
@@ -19,4 +19,13 @@ describe('class schedule display', () => {
     );
     assert.equal(formatClassSchedule({}), '');
   });
+
+  it('calculates class end date from start date, days and number of sessions', () => {
+    // 1403/01/01 is Wednesday (day 3)
+    // If days are [6, 2] (Saturday, Tuesday), 2 sessions:
+    // Session 1: Saturday 1403/01/04
+    // Session 2: Tuesday 1403/01/07
+    const endDate = calculateClassEndDate('1403/01/01', [6, 2], 2);
+    assert.equal(endDate, '1403/01/07');
+  });
 });