refactor(work-orders): 코드 리뷰 기반 전면 개선

## Critical 수정
- Multi-tenancy: WorkOrderItem, BendingDetail, Issue에 BelongsToTenant 적용
- 감사 로그: 상태변경, 품목수정, 이슈 등록/해결 시 로깅 추가
- 상태 전이 규칙: STATUS_TRANSITIONS + canTransitionTo() 구현

## High 수정
- 다중 담당자: work_order_assignees 피벗 테이블 및 관계 추가
- 부분 수정: 품목 ID 기반 upsert/delete 로직 구현

## 변경 파일
- Models: WorkOrder, WorkOrderAssignee(신규), 하위 모델들
- Services: WorkOrderService (assign, update 메서드 개선)
- Migrations: tenant_id 추가, assignees 테이블 생성

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

app/Services/WorkOrderService.php

@@ -3,13 +3,21 @@
 namespace App\Services;
 
 use App\Models\Production\WorkOrder;
+use App\Models\Production\WorkOrderAssignee;
 use App\Models\Production\WorkOrderBendingDetail;
+use App\Services\Audit\AuditLogger;
 use Illuminate\Support\Facades\DB;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
 class WorkOrderService extends Service
 {
+    private const AUDIT_TARGET = 'work_order';
+
+    public function __construct(
+        private readonly AuditLogger $auditLogger
+    ) {}
+
     /**
      * 목록 조회 (검색/필터링/페이징)
      */
@@ -29,7 +37,7 @@ public function index(array $params)
 
         $query = WorkOrder::query()
             ->where('tenant_id', $tenantId)
-            ->with(['assignee:id,name', 'team:id,name', 'salesOrder:id,order_no']);
+            ->with(['assignee:id,name', 'assignees.user:id,name', 'team:id,name', 'salesOrder:id,order_no']);
 
         // 검색어
         if ($q !== '') {
@@ -106,6 +114,7 @@ public function show(int $id)
         $workOrder = WorkOrder::where('tenant_id', $tenantId)
             ->with([
                 'assignee:id,name',
+                'assignees.user:id,name',
                 'team:id,name',
                 'salesOrder:id,order_no,project_name',
                 'items',
@@ -149,16 +158,28 @@ public function store(array $data)
 
             // 품목 저장
             foreach ($items as $index => $item) {
+                $item['tenant_id'] = $tenantId;
                 $item['sort_order'] = $index;
                 $workOrder->items()->create($item);
             }
 
             // 벤딩 상세 저장 (벤딩 공정인 경우)
             if ($data['process_type'] === WorkOrder::PROCESS_BENDING && $bendingDetail) {
+                $bendingDetail['tenant_id'] = $tenantId;
                 $workOrder->bendingDetail()->create($bendingDetail);
             }
 
-            return $workOrder->load(['assignee:id,name', 'team:id,name', 'items', 'bendingDetail']);
+            // 감사 로그
+            $this->auditLogger->log(
+                $tenantId,
+                self::AUDIT_TARGET,
+                $workOrder->id,
+                'created',
+                null,
+                $workOrder->toArray()
+            );
+
+            return $workOrder->load(['assignee:id,name', 'assignees.user:id,name', 'team:id,name', 'items', 'bendingDetail']);
         });
     }
 
@@ -175,33 +196,89 @@ public function update(int $id, array $data)
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
-        return DB::transaction(function () use ($workOrder, $data, $userId) {
+        $beforeData = $workOrder->toArray();
+
+        return DB::transaction(function () use ($workOrder, $data, $userId, $beforeData) {
             $data['updated_by'] = $userId;
 
             $items = $data['items'] ?? null;
             $bendingDetail = $data['bending_detail'] ?? null;
             unset($data['items'], $data['bending_detail'], $data['work_order_no']); // 번호 변경 불가
 
+            // 품목 수정 시 기존 품목 기록
+            $oldItems = null;
+            if ($items !== null) {
+                $oldItems = $workOrder->items()->get()->toArray();
+            }
+
             $workOrder->update($data);
 
-            // 품목 교체 (있는 경우)
+            // 품목 부분 수정 (ID 기반 upsert/delete)
             if ($items !== null) {
-                $workOrder->items()->delete();
+                $existingIds = $workOrder->items()->pluck('id')->toArray();
+                $incomingIds = [];
+
                 foreach ($items as $index => $item) {
-                    $item['sort_order'] = $index;
-                    $workOrder->items()->create($item);
+                    $itemData = [
+                        'tenant_id' => $workOrder->tenant_id,
+                        'item_name' => $item['item_name'] ?? null,
+                        'specification' => $item['specification'] ?? null,
+                        'quantity' => $item['quantity'] ?? 1,
+                        'unit' => $item['unit'] ?? null,
+                        'sort_order' => $index,
+                    ];
+
+                    if (isset($item['id']) && $item['id']) {
+                        // ID가 있으면 업데이트
+                        $existingItem = $workOrder->items()->find($item['id']);
+                        if ($existingItem) {
+                            $existingItem->update($itemData);
+                            $incomingIds[] = (int) $item['id'];
+                        }
+                    } else {
+                        // ID가 없으면 신규 생성
+                        $newItem = $workOrder->items()->create($itemData);
+                        $incomingIds[] = $newItem->id;
+                    }
                 }
+
+                // 요청에 없는 기존 품목 삭제
+                $toDelete = array_diff($existingIds, $incomingIds);
+                if (! empty($toDelete)) {
+                    $workOrder->items()->whereIn('id', $toDelete)->delete();
+                }
+
+                // 품목 수정 감사 로그
+                $this->auditLogger->log(
+                    $workOrder->tenant_id,
+                    self::AUDIT_TARGET,
+                    $workOrder->id,
+                    'items_updated',
+                    ['items' => $oldItems],
+                    ['items' => $workOrder->items()->get()->toArray()]
+                );
             }
 
             // 벤딩 상세 업데이트
             if ($bendingDetail !== null && $workOrder->process_type === WorkOrder::PROCESS_BENDING) {
+                $bendingDetail['tenant_id'] = $workOrder->tenant_id;
                 $workOrder->bendingDetail()->updateOrCreate(
                     ['work_order_id' => $workOrder->id],
                     $bendingDetail
                 );
             }
 
-            return $workOrder->load(['assignee:id,name', 'team:id,name', 'items', 'bendingDetail']);
+            // 수정 감사 로그
+            $this->auditLogger->log(
+                $workOrder->tenant_id,
+                self::AUDIT_TARGET,
+                $workOrder->id,
+                'updated',
+                $beforeData,
+                $workOrder->fresh()->toArray()
+            );
+
+            return $workOrder->load(['assignee:id,name', 'assignees.user:id,name', 'team:id,name', 'items', 'bendingDetail']);
         });
     }
 
@@ -226,8 +303,19 @@ public function destroy(int $id)
             throw new BadRequestHttpException(__('error.work_order.cannot_delete_in_progress'));
         }
 
+        $beforeData = $workOrder->toArray();
         $workOrder->delete();
 
+        // 삭제 감사 로그
+        $this->auditLogger->log(
+            $tenantId,
+            self::AUDIT_TARGET,
+            $workOrder->id,
+            'deleted',
+            $beforeData,
+            null
+        );
+
         return 'success';
     }
 
@@ -249,6 +337,19 @@ public function updateStatus(int $id, string $status)
             throw new BadRequestHttpException(__('error.invalid_status'));
         }
 
+        // 상태 전이 규칙 검증
+        if (! $workOrder->canTransitionTo($status)) {
+            $allowed = implode(', ', $workOrder->getAllowedTransitions());
+            throw new BadRequestHttpException(
+                __('error.work_order.invalid_transition', [
+                    'from' => $workOrder->status,
+                    'to' => $status,
+                    'allowed' => $allowed,
+                ])
+            );
+        }
+
+        $oldStatus = $workOrder->status;
         $workOrder->status = $status;
         $workOrder->updated_by = $userId;
 
@@ -267,11 +368,24 @@ public function updateStatus(int $id, string $status)
 
         $workOrder->save();
 
-        return $workOrder->load(['assignee:id,name', 'team:id,name']);
+        // 상태 변경 감사 로그
+        $this->auditLogger->log(
+            $tenantId,
+            self::AUDIT_TARGET,
+            $workOrder->id,
+            'status_changed',
+            ['status' => $oldStatus],
+            ['status' => $status]
+        );
+
+        return $workOrder->load(['assignee:id,name', 'assignees.user:id,name', 'team:id,name']);
     }
 
     /**
-     * 담당자 배정
+     * 담당자 배정 (다중 담당자 지원)
+     *
+     * @param  int  $id  작업지시 ID
+     * @param  array  $data  배정 데이터 (assignee_ids: int[], team_id?: int)
      */
     public function assign(int $id, array $data)
     {
@@ -283,18 +397,65 @@ public function assign(int $id, array $data)
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
-        $workOrder->assignee_id = $data['assignee_id'];
-        $workOrder->team_id = $data['team_id'] ?? $workOrder->team_id;
-        $workOrder->updated_by = $userId;
+        return DB::transaction(function () use ($workOrder, $data, $tenantId, $userId) {
+            // 이전 상태 기록
+            $beforeAssignees = $workOrder->assignees()->pluck('user_id')->toArray();
+            $beforePrimaryAssignee = $workOrder->assignee_id;
+            $beforeTeam = $workOrder->team_id;
 
-        // 미배정이었으면 대기로 변경
-        if ($workOrder->status === WorkOrder::STATUS_UNASSIGNED) {
-            $workOrder->status = WorkOrder::STATUS_PENDING;
-        }
+            // 담당자 ID 배열 처리 (단일 값도 배열로 변환)
+            $assigneeIds = $data['assignee_ids'] ?? [];
+            if (isset($data['assignee_id']) && ! empty($data['assignee_id'])) {
+                // 하위 호환: 단일 assignee_id도 지원
+                $assigneeIds = is_array($data['assignee_id']) ? $data['assignee_id'] : [$data['assignee_id']];
+            }
+            $assigneeIds = array_unique(array_filter($assigneeIds));
 
-        $workOrder->save();
+            // 기존 담당자 삭제 후 새로 추가
+            $workOrder->assignees()->delete();
 
-        return $workOrder->load(['assignee:id,name', 'team:id,name']);
+            foreach ($assigneeIds as $index => $assigneeId) {
+                WorkOrderAssignee::create([
+                    'tenant_id' => $tenantId,
+                    'work_order_id' => $workOrder->id,
+                    'user_id' => $assigneeId,
+                    'is_primary' => $index === 0, // 첫 번째가 주 담당자
+                ]);
+            }
+
+            // 주 담당자는 work_orders 테이블에도 설정 (하위 호환)
+            $primaryAssigneeId = $assigneeIds[0] ?? null;
+            $workOrder->assignee_id = $primaryAssigneeId;
+            $workOrder->team_id = $data['team_id'] ?? $workOrder->team_id;
+            $workOrder->updated_by = $userId;
+
+            // 미배정이었으면 대기로 변경
+            if ($workOrder->status === WorkOrder::STATUS_UNASSIGNED && $primaryAssigneeId) {
+                $workOrder->status = WorkOrder::STATUS_PENDING;
+            }
+
+            $workOrder->save();
+
+            // 배정 감사 로그
+            $this->auditLogger->log(
+                $tenantId,
+                self::AUDIT_TARGET,
+                $workOrder->id,
+                'assigned',
+                [
+                    'assignee_id' => $beforePrimaryAssignee,
+                    'assignee_ids' => $beforeAssignees,
+                    'team_id' => $beforeTeam,
+                ],
+                [
+                    'assignee_id' => $workOrder->assignee_id,
+                    'assignee_ids' => $assigneeIds,
+                    'team_id' => $workOrder->team_id,
+                ]
+            );
+
+            return $workOrder->load(['assignee:id,name', 'assignees.user:id,name', 'team:id,name']);
+        });
     }
 
     /**
@@ -315,15 +476,28 @@ public function toggleBendingField(int $id, string $field)
 
         $detail = $workOrder->bendingDetail;
         if (! $detail) {
-            $detail = $workOrder->bendingDetail()->create([]);
+            $detail = $workOrder->bendingDetail()->create([
+                'tenant_id' => $workOrder->tenant_id,
+            ]);
         }
 
         if (! in_array($field, WorkOrderBendingDetail::PROCESS_FIELDS)) {
             throw new BadRequestHttpException(__('error.invalid_field'));
         }
 
+        $beforeValue = $detail->{$field};
         $detail->toggleField($field);
 
+        // 벤딩 토글 감사 로그
+        $this->auditLogger->log(
+            $workOrder->tenant_id,
+            self::AUDIT_TARGET,
+            $workOrder->id,
+            'bending_toggled',
+            [$field => $beforeValue],
+            [$field => $detail->{$field}]
+        );
+
         return $detail;
     }
 
@@ -340,9 +514,22 @@ public function addIssue(int $workOrderId, array $data)
             throw new NotFoundHttpException(__('error.not_found'));
         }
 
+        $data['tenant_id'] = $tenantId;
         $data['reported_by'] = $userId;
 
-        return $workOrder->issues()->create($data);
+        $issue = $workOrder->issues()->create($data);
+
+        // 이슈 추가 감사 로그
+        $this->auditLogger->log(
+            $tenantId,
+            self::AUDIT_TARGET,
+            $workOrderId,
+            'issue_added',
+            null,
+            ['issue_id' => $issue->id, 'title' => $issue->title, 'priority' => $issue->priority]
+        );
+
+        return $issue;
     }
 
     /**
@@ -365,6 +552,16 @@ public function resolveIssue(int $workOrderId, int $issueId)
 
         $issue->resolve($userId);
 
+        // 이슈 해결 감사 로그
+        $this->auditLogger->log(
+            $tenantId,
+            self::AUDIT_TARGET,
+            $workOrderId,
+            'issue_resolved',
+            ['issue_id' => $issueId, 'status' => 'open'],
+            ['issue_id' => $issueId, 'status' => 'resolved', 'resolved_by' => $userId]
+        );
+
         return $issue;
     }