fix: 배포 후 버그 수정 — 테이블명/컬럼명 불일치, navbar active, API 검증 강화, 대시보드 통계 라우트 추가

- checkinModel: partner_checkins → partner_work_checkins, countActive() 추가
- workReportModel: partner_work_reports → daily_work_reports
- partner-portal: check_out_at/check_in_at → check_out_time/check_in_time
- checkinModel findTodayByCompany: LEFT JOIN has_work_report
- tkpurchase-core/tksafety-core: navbar match '' 제거
- checkinController: checkOut에 업무현황 검증, stats() 추가
- workReportController: checkin_id 필수 + schedule 일치 검증
- checkinRoutes: GET / 대시보드 통계 라우트 추가
- nginx.conf: visit.html → tksafety 리다이렉트
- migration-purchase-safety.sql: DDL 동기화
- migration-purchase-safety-patch.sql: 신규 패치

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

tksafety/web/static/js/tksafety-core.js

@@ -83,7 +83,7 @@ function doLogout() {
 function renderNavbar() {
     const currentPage = location.pathname.replace(/\//g, '') || 'index.html';
     const links = [
-        { href: '/', icon: 'fa-door-open', label: '방문 관리', match: ['', 'index.html'] },
+        { href: '/', icon: 'fa-door-open', label: '방문 관리', match: ['index.html'] },
         { href: '/education.html', icon: 'fa-graduation-cap', label: '안전교육', match: ['education.html'] },
     ];
     const nav = document.getElementById('sideNav');