feat: [leaves] 휴가신청 → 전자결재 자동 연동

- LeaveService: 휴가 신청 시 결재 자동 생성+상신
- LeaveService: approveByApproval/rejectByApproval 메서드 추가
- LeaveService: deletePendingLeave 시 연결된 결재 자동 취소
- ApprovalService: 승인/반려/회수/전결 시 휴가 상태 자동 동기화
- Leave 모델: approval_id, approval() 관계 추가
- UI: pending 휴가에 결재 상세 링크 추가, 승인/반려 버튼 제거

resources/views/hr/leaves/index.blade.php

@@ -8,7 +8,7 @@
     <div class="flex flex-col lg:flex-row lg:justify-between lg:items-center gap-4 mb-6">
         <div>
             <h1 class="text-2xl font-bold text-gray-800">휴가관리</h1>
-            <p class="text-sm text-gray-500 mt-1">휴가 신청, 승인/반려 및 연차 현황을 관리합니다.</p>
+            <p class="text-sm text-gray-500 mt-1">휴가 신청 시 결재가 자동 생성되며, 결재 승인/반려에 따라 휴가가 처리됩니다.</p>
         </div>
         <div class="flex flex-wrap items-center gap-2 sm:gap-3">
             <button type="button" onclick="openLeaveModal()"

resources/views/hr/leaves/partials/table.blade.php

@@ -91,8 +91,21 @@
 
                 {{-- 액션 --}}
                 <td class="px-6 py-4 whitespace-nowrap text-center">
-                    @if($leave->status === 'pending')
-                        <div class="flex items-center justify-center gap-1">
+                    <div class="flex items-center justify-center gap-1">
+                        @if($leave->approval_id)
+                            <a href="{{ route('approvals.show', $leave->approval_id) }}"
+                               class="px-2.5 py-1 text-xs font-medium text-blue-700 bg-blue-50 hover:bg-blue-100 rounded transition-colors">
+                                결재 상세 →
+                            </a>
+                        @endif
+
+                        @if($leave->status === 'approved')
+                            <button type="button" onclick="cancelLeave({{ $leave->id }})"
+                                    class="px-2.5 py-1 text-xs font-medium text-gray-700 bg-gray-100 hover:bg-gray-200 rounded transition-colors">
+                                취소
+                            </button>
+                        @elseif($leave->status === 'pending' && !$leave->approval_id)
+                            {{-- 결재 연동 없는 기존 pending 건만 직접 승인/반려 허용 --}}
                             <button type="button" onclick="approveLeave({{ $leave->id }})"
                                     class="px-2.5 py-1 text-xs font-medium text-emerald-700 bg-emerald-50 hover:bg-emerald-100 rounded transition-colors">
                                 승인
@@ -101,15 +114,10 @@ class="px-2.5 py-1 text-xs font-medium text-emerald-700 bg-emerald-50 hover:bg-e
                                     class="px-2.5 py-1 text-xs font-medium text-red-700 bg-red-50 hover:bg-red-100 rounded transition-colors">
                                 반려
                             </button>
-                        </div>
-                    @elseif($leave->status === 'approved')
-                        <button type="button" onclick="cancelLeave({{ $leave->id }})"
-                                class="px-2.5 py-1 text-xs font-medium text-gray-700 bg-gray-100 hover:bg-gray-200 rounded transition-colors">
-                            취소
-                        </button>
-                    @else
-                        <span class="text-xs text-gray-400">-</span>
-                    @endif
+                        @elseif(!$leave->approval_id && $leave->status !== 'pending' && $leave->status !== 'approved')
+                            <span class="text-xs text-gray-400">-</span>
+                        @endif
+                    </div>
                 </td>
             </tr>
             @empty