fix(sprint004-b): initAuth() 추가 + getSSOToken + 캐시 버스팅

- monthly-comparison.html: initAuth() 호출 추가 (인증/사용자 정보 로드)
- monthly-comparison.js: 엑셀 다운로드 토큰을 getSSOToken으로 전환
- 캐시 버스팅: ?v=2026033102

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

system1-factory/web/js/monthly-comparison.js

@@ -481,7 +481,7 @@ async function downloadExcel() {
             showToast('Mock 모드에서는 다운로드를 지원하지 않습니다', 'info');
             return;
         }
-        const token = localStorage.getItem('sso_token') || '';
+        const token = (window.getSSOToken && window.getSSOToken()) || '';
         const response = await fetch(`${window.API_BASE_URL}/monthly-comparison/export?year=${currentYear}&month=${currentMonth}`, {
             headers: { 'Authorization': `Bearer ${token}` }
         });

system1-factory/web/pages/attendance/monthly-comparison.html

@@ -159,6 +159,7 @@
 
     <script src="/static/js/tkfb-core.js?v=2026033001"></script>
     <script src="/js/api-base.js?v=2026031701"></script>
-    <script src="/js/monthly-comparison.js?v=2026033001"></script>
+    <script src="/js/monthly-comparison.js?v=2026033102"></script>
+    <script>initAuth();</script>
 </body>
 </html>