refactor(gateway): gateway↔system1 분리 — gateway=문짝, system1-web=독립

gateway에서 system1 프록시 제거, 대시보드+로그인+공유JS만 담당.
system1-web에 /auth/, /ai-api/ 프록시 이관. tkds-web 제거(gateway 흡수).
notification-bell URL tkfb→tkds, system3 로그인 URL tkds/dashboard로 변경.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tkpurchase/web/static/js/tkpurchase-core.js

@@ -156,6 +156,6 @@ function initAuth() {
 /* ===== 알림 벨 ===== */
 function _loadNotificationBell() {
     const s = document.createElement('script');
-    s.src = (location.hostname.includes('technicalkorea.net') ? 'https://tkfb.technicalkorea.net' : location.protocol + '//' + location.hostname + ':30000') + '/shared/notification-bell.js?v=2';
+    s.src = (location.hostname.includes('technicalkorea.net') ? 'https://tkds.technicalkorea.net' : location.protocol + '//' + location.hostname + ':30000') + '/shared/notification-bell.js?v=3';
     document.head.appendChild(s);
 }