fix: 캘린더 모달 중복 카드 문제 및 삭제 권한 개선

- monthly_worker_status 조회 시 GROUP BY로 중복 데이터 합산
- 작업보고서 삭제 권한을 그룹장 이상으로 제한 (admin, system, group_leader)
- 중복 데이터 정리를 위한 마이그레이션 SQL 추가 (009_fix_duplicate_monthly_status.sql)
- synology_deployment 버전에도 동일 수정 적용

web-ui/css/common.css

@@ -1,5 +1,62 @@
 /* Common CSS - 공통 스타일 */
 
+/* ========== 통일된 헤더 스타일 ========== */
+.work-report-container {
+  min-height: 100vh;
+  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
+}
+
+.work-report-header {
+  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+  color: white;
+  text-align: center;
+  padding: 3rem 2rem;
+  margin-bottom: 0;
+}
+
+.work-report-header h1 {
+  font-size: 2.5rem;
+  font-weight: 700;
+  margin: 0 0 1rem 0;
+  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
+}
+
+.work-report-header .subtitle {
+  font-size: 1.1rem;
+  opacity: 0.9;
+  margin: 0;
+  font-weight: 300;
+}
+
+.work-report-main {
+  background: #f8f9fa;
+  min-height: calc(100vh - 200px);
+  padding-top: 2rem;
+}
+
+.back-button {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.75rem 1.5rem;
+  background: rgba(255, 255, 255, 0.9);
+  color: #495057;
+  text-decoration: none;
+  border-radius: 8px;
+  font-weight: 500;
+  margin: 0 2rem 2rem 2rem;
+  transition: all 0.3s ease;
+  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
+}
+
+.back-button:hover {
+  background: white;
+  color: #007bff;
+  transform: translateY(-1px);
+  box-shadow: 0 4px 8px rgba(0,0,0,0.15);
+}
+
 /* Reset and Base Styles */
 * {
   margin: 0;
@@ -28,6 +85,42 @@ h4 { font-size: 1.125rem; }
 h5 { font-size: 1rem; }
 h6 { font-size: 0.875rem; }
 
+/* ========== 헤더 액션 버튼 ========== */
+.header-actions {
+  display: flex;
+  align-items: center;
+  gap: 1rem;
+  margin-right: 1rem;
+}
+
+.dashboard-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.6rem 1.2rem;
+  background: rgba(255, 255, 255, 0.15);
+  color: white;
+  border: 1px solid rgba(255, 255, 255, 0.3);
+  border-radius: 8px;
+  font-size: 0.9rem;
+  font-weight: 500;
+  text-decoration: none;
+  cursor: pointer;
+  transition: all 0.3s ease;
+  backdrop-filter: blur(10px);
+}
+
+.dashboard-btn:hover {
+  background: rgba(255, 255, 255, 0.25);
+  border-color: rgba(255, 255, 255, 0.5);
+  transform: translateY(-1px);
+  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
+}
+
+.dashboard-btn .btn-icon {
+  font-size: 1rem;
+}
+
 /* Buttons */
 .btn {
   display: inline-flex;