refactor(item-master): 독립 엔티티 아키텍처 적용 및 Swagger 보완

- FK 컬럼 제거: item_sections.page_id, item_fields.section_id, item_bom_items.section_id
- entity_relationships 테이블로 전환하여 독립 엔티티 구조 확립
- ItemMasterField 관련 파일 삭제 (Controller, Service, Model, Requests)
- destroy 메서드 독립 엔티티 아키텍처 적용 (관계 링크만 삭제)
- Swagger 스키마에서 FK 참조 제거
- FormRequest 및 Swagger에 group_id(계층번호) 필드 추가

app/Http/Requests/ItemMaster/ItemBomItemStoreRequest.php

@@ -14,6 +14,7 @@ public function authorize(): bool
     public function rules(): array
     {
         return [
+            'group_id' => 'nullable|integer|min:1', // 계층번호
             'item_code' => 'nullable|string|max:100',
             'item_name' => 'required|string|max:255',
             'quantity' => 'nullable|numeric|min:0',

app/Http/Requests/ItemMaster/ItemFieldStoreRequest.php

@@ -14,6 +14,7 @@ public function authorize(): bool
     public function rules(): array
     {
         return [
+            'group_id' => 'nullable|integer|min:1', // 계층번호
             'field_name' => 'required|string|max:255',
             'field_type' => 'required|in:textbox,number,dropdown,checkbox,date,textarea',
             'is_required' => 'nullable|boolean',

app/Http/Requests/ItemMaster/ItemMasterFieldStoreRequest.php

@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Requests\ItemMaster;
-
-use Illuminate\Foundation\Http\FormRequest;
-
-class ItemMasterFieldStoreRequest extends FormRequest
-{
-    public function authorize(): bool
-    {
-        return true;
-    }
-
-    public function rules(): array
-    {
-        return [
-            'field_name' => 'required|string|max:255',
-            'field_type' => 'required|in:textbox,number,dropdown,checkbox,date,textarea',
-            'category' => 'nullable|string|max:100',
-            'description' => 'nullable|string',
-            'is_common' => 'nullable|boolean',
-            'default_value' => 'nullable|string',
-            'options' => 'nullable|array',
-            'validation_rules' => 'nullable|array',
-            'properties' => 'nullable|array',
-        ];
-    }
-}

app/Http/Requests/ItemMaster/ItemMasterFieldUpdateRequest.php

@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Http\Requests\ItemMaster;
-
-use Illuminate\Foundation\Http\FormRequest;
-
-class ItemMasterFieldUpdateRequest extends FormRequest
-{
-    public function authorize(): bool
-    {
-        return true;
-    }
-
-    public function rules(): array
-    {
-        return [
-            'field_name' => 'sometimes|string|max:255',
-            'field_type' => 'sometimes|in:textbox,number,dropdown,checkbox,date,textarea',
-            'category' => 'sometimes|nullable|string|max:100',
-            'description' => 'sometimes|nullable|string',
-            'is_common' => 'sometimes|nullable|boolean',
-            'default_value' => 'sometimes|nullable|string',
-            'options' => 'sometimes|nullable|array',
-            'validation_rules' => 'sometimes|nullable|array',
-            'properties' => 'sometimes|nullable|array',
-        ];
-    }
-}

app/Http/Requests/ItemMaster/ItemSectionStoreRequest.php

@@ -14,6 +14,7 @@ public function authorize(): bool
     public function rules(): array
     {
         return [
+            'group_id' => 'nullable|integer|min:1', // 계층번호
             'title' => 'required|string|max:255',
             'type' => 'required|in:fields,bom',
         ];