feat(tkuser): 협력업체 완전삭제 기능 추가 (admin 전용)

- 관련 데이터 cascade 삭제 (workers, schedules, checkins, reports, SSO 계정 등)
- 구매 이력 있는 업체는 삭제 차단
- 프론트엔드: 목록/상세에 완전삭제 버튼 + prompt("삭제") 안전장치

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

user-management/web/index.html

@@ -2009,7 +2009,7 @@
     <script src="/static/js/tkuser-tasks.js?v=2026031401"></script>
     <script src="/static/js/tkuser-vacations.js?v=2026031401"></script>
     <script src="/static/js/tkuser-layout-map.js?v=2026031401"></script>
-    <script src="/static/js/tkuser-partners.js?v=2026031401"></script>
+    <script src="/static/js/tkuser-partners.js?v=2026031601"></script>
     <script src="/static/js/tkuser-vendors.js?v=2026031401"></script>
     <script src="/static/js/tkuser-consumables.js?v=2026031401"></script>
     <script src="/static/js/tkuser-notificationRecipients.js?v=2026031401"></script>