feat(sprint005): 월간 확인 워크플로우 — 관리자 확인요청 + 수정요청

- DB: status ENUM 확장 (review_sent, change_request) + reviewed_by/at, change_details
- API: POST /review-send (일괄 확인요청), POST /review-respond (수정 승인/거부)
- 작업자: pending=검토대기, review_sent=확인/수정요청, rejected=동의(재확인)
- 관리자: 필터 탭 확장 + 확인요청 일괄 발송 버튼
- confirm 상태 전환 검증: pending→confirmed 차단

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

system1-factory/web/pages/attendance/monthly-comparison.html

@@ -94,12 +94,15 @@
               <div class="mc-progress-bar"><div class="mc-progress-fill" id="progressFill"></div></div>
               <div class="mc-progress-text" id="progressText"></div>
               <div class="mc-status-counts" id="statusCounts"></div>
+              <button type="button" class="mc-review-send-btn hidden" id="reviewSendBtn" onclick="sendReviewAll()" style="margin-top:8px;width:100%;padding:10px;background:#2563eb;color:white;border:none;border-radius:8px;font-size:0.8rem;font-weight:600;cursor:pointer;">확인요청 발송</button>
             </div>
 
             <div class="mc-filter-tabs">
               <button class="mc-tab active" data-filter="all" onclick="filterWorkers('all')">전체</button>
               <button class="mc-tab" data-filter="confirmed" onclick="filterWorkers('confirmed')">확인</button>
-              <button class="mc-tab" data-filter="pending" onclick="filterWorkers('pending')">대기</button>
+              <button class="mc-tab" data-filter="review_sent" onclick="filterWorkers('review_sent')">확인요청</button>
+              <button class="mc-tab" data-filter="pending" onclick="filterWorkers('pending')">미검토</button>
+              <button class="mc-tab" data-filter="change_request" onclick="filterWorkers('change_request')">수정요청</button>
               <button class="mc-tab" data-filter="rejected" onclick="filterWorkers('rejected')">반려</button>
             </div>
 
@@ -159,7 +162,7 @@
 
     <script src="/static/js/tkfb-core.js?v=2026033108"></script>
     <script src="/js/api-base.js?v=2026031701"></script>
-    <script src="/js/monthly-comparison.js?v=2026033107"></script>
+    <script src="/js/monthly-comparison.js?v=2026040101"></script>
     <script>initAuth();</script>
 </body>
 </html>