feat: Phase 5 - 참조 테이블 모델 item_id 마이그레이션

- Order 모델: product_id 제거, item_id 추가, item() 관계 추가
- OrderItem 모델: product_id 제거, item_id 추가, item() 관계 추가
- Quote 모델: product_id 제거, item_id 추가, item() 관계 추가
- MaterialReceipt 모델: material_id 제거, item_id 추가, material() → item() 변경
- Lot 모델: Material import 제거, material() → item() 변경

DB 스키마는 이미 마이그레이션됨 (2025_12_13_153544)
기존 product_id/material_id 컬럼은 DB에 남아있지만 fillable에서 제거

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/Models/Materials/MaterialReceipt.php

@@ -2,6 +2,7 @@
 
 namespace App\Models\Materials;
 
+use App\Models\Items\Item;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 
@@ -13,15 +14,15 @@ class MaterialReceipt extends Model
     use SoftDeletes;
 
     protected $fillable = [
-        'material_id', 'receipt_date', 'lot_number', 'received_qty', 'unit',
+        'item_id', 'receipt_date', 'lot_number', 'received_qty', 'unit',
         'supplier_name', 'manufacturer_name', 'purchase_price_excl_vat',
         'weight_kg', 'status_code', 'is_inspection', 'inspection_date', 'remarks',
     ];
 
-    // 자재 마스터
-    public function material()
+    // 품목 (통합 items 테이블)
+    public function item()
     {
-        return $this->belongsTo(Material::class, 'material_id');
+        return $this->belongsTo(Item::class, 'item_id');
     }
 
     // 수입검사 내역

app/Models/Orders/Order.php

@@ -2,6 +2,7 @@
 
 namespace App\Models\Orders;
 
+use App\Models\Items\Item;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 
@@ -16,7 +17,7 @@ class Order extends Model
     protected $table = 'orders';
 
     protected $fillable = [
-        'tenant_id', 'order_no', 'order_type_code', 'status_code', 'category_code', 'product_id',
+        'tenant_id', 'order_no', 'order_type_code', 'status_code', 'category_code', 'item_id',
         'received_at', 'writer_id', 'client_id', 'client_contact', 'site_name', 'quantity', 'delivery_date',
         'delivery_method_code', 'memo',
     ];
@@ -38,4 +39,10 @@ public function versions()
     {
         return $this->hasMany(OrderVersion::class);
     }
+
+    // 품목 (통합 items 테이블)
+    public function item()
+    {
+        return $this->belongsTo(Item::class, 'item_id');
+    }
 }

app/Models/Orders/OrderItem.php

@@ -2,6 +2,7 @@
 
 namespace App\Models\Orders;
 
+use App\Models\Items\Item;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 
@@ -16,7 +17,7 @@ class OrderItem extends Model
     protected $table = 'order_items';
 
     protected $fillable = [
-        'tenant_id', 'order_id', 'serial_no', 'product_id', 'quantity',
+        'tenant_id', 'order_id', 'serial_no', 'item_id', 'quantity',
         'status_code', 'design_code', 'remarks', 'attributes',
     ];
 
@@ -30,4 +31,10 @@ public function order()
     {
         return $this->belongsTo(Order::class);
     }
+
+    // 품목 (통합 items 테이블)
+    public function item()
+    {
+        return $this->belongsTo(Item::class, 'item_id');
+    }
 }

app/Models/Qualitys/Lot.php

@@ -2,7 +2,7 @@
 
 namespace App\Models\Qualitys;
 
-use App\Models\Materials\Material;
+use App\Models\Items\Item;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\SoftDeletes;
 
@@ -13,10 +13,10 @@ class Lot extends Model
 {
     use SoftDeletes;
 
-    // 자재 마스터
-    public function material()
+    // 품목 (통합 items 테이블)
+    public function item()
     {
-        return $this->belongsTo(Material::class, 'material_id');
+        return $this->belongsTo(Item::class, 'item_id');
     }
 
     // 판매 기록

app/Models/Quote/Quote.php

@@ -2,6 +2,7 @@
 
 namespace App\Models\Quote;
 
+use App\Models\Items\Item;
 use App\Models\Members\User;
 use App\Models\Orders\Client;
 use App\Traits\BelongsToTenant;
@@ -32,7 +33,7 @@ class Quote extends Model
         'site_code',
         // 제품 정보
         'product_category',
-        'product_id',
+        'item_id',
         'product_code',
         'product_name',
         // 규격 정보
@@ -133,6 +134,14 @@ public function client(): BelongsTo
         return $this->belongsTo(Client::class);
     }
 
+    /**
+     * 품목 (통합 items 테이블)
+     */
+    public function item(): BelongsTo
+    {
+        return $this->belongsTo(Item::class, 'item_id');
+    }
+
     /**
      * 확정자
      */