feat(tkuser): Sprint 001 Section A — 연차/휴가 백엔드 전환 (DB + API)

workers/vacation_balance_details → sso_users/sp_vacation_balances 기반 전환.
부서장 설정, 승인권한 CRUD, vacation_settings 테이블, 장기근속 자동부여,
startup migration 추가.

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

user-management/api/routes/vacationSettingsRoutes.js

@@ -0,0 +1,15 @@
+/**
+ * Vacation Settings Routes
+ *
+ * 연차 계산 규칙 설정
+ */
+
+const express = require('express');
+const router = express.Router();
+const vsc = require('../controllers/vacationSettingsController');
+const { requireAuth, requireAdmin } = require('../middleware/auth');
+
+router.get('/', requireAuth, vsc.getSettings);
+router.put('/', requireAdmin, vsc.updateSettings);
+
+module.exports = router;