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/api/controllers/partnerController.js

@@ -119,7 +119,32 @@ async function deactivateWorker(req, res) {
   }
 }
 
+async function getDeleteInfo(req, res) {
+  try {
+    const company = await partnerModel.findById(req.params.id);
+    if (!company) return res.status(404).json({ success: false, error: '업체를 찾을 수 없습니다' });
+    const info = await partnerModel.getDeleteInfo(req.params.id);
+    res.json({ success: true, data: { company_name: company.company_name, ...info } });
+  } catch (err) {
+    console.error('Partner getDeleteInfo error:', err);
+    res.status(500).json({ success: false, error: err.message });
+  }
+}
+
+async function permanentDelete(req, res) {
+  try {
+    const company = await partnerModel.findById(req.params.id);
+    if (!company) return res.status(404).json({ success: false, error: '업체를 찾을 수 없습니다' });
+    await partnerModel.permanentDelete(req.params.id, req.user.id);
+    res.json({ success: true, message: `"${company.company_name}" 업체가 완전히 삭제되었습니다` });
+  } catch (err) {
+    console.error('Partner permanentDelete error:', err);
+    res.status(500).json({ success: false, error: err.message });
+  }
+}
+
 module.exports = {
   list, getById, create, update, deactivate,
-  listWorkers, createWorker, updateWorker, deactivateWorker
+  listWorkers, createWorker, updateWorker, deactivateWorker,
+  getDeleteInfo, permanentDelete
 };