fix: [품질관리] 수주선택 모달 납품일 포맷 및 개소 수 수정

- delivery_date: ISO 타임스탬프 → Y-m-d 포맷으로 변환
- location_count: order_items 수 → order_nodes 루트 노드(개소) 수로 변경

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

app/Services/QualityDocumentService.php

@@ -347,8 +347,9 @@ public function availableOrders(array $params): array
 
         $query = Order::where('tenant_id', $tenantId)
             ->whereNotIn('id', $linkedOrderIds)
-            ->with(['items'])
-            ->withCount('items');
+            ->withCount(['nodes as location_count' => function ($q) {
+                $q->whereNull('parent_id');
+            }]);
 
         if ($q !== '') {
             $query->where(function ($qq) use ($q) {
@@ -364,8 +365,8 @@ public function availableOrders(array $params): array
                 'id' => $order->id,
                 'order_number' => $order->order_no,
                 'site_name' => $order->site_name ?? '',
-                'delivery_date' => $order->delivery_date ?? '',
-                'location_count' => $order->items_count,
+                'delivery_date' => $order->delivery_date?->format('Y-m-d') ?? '',
+                'location_count' => $order->location_count,
             ])
             ->toArray();
     }