feat: [item-master] 항목 탭 검색 기능 추가

- 항목명, 입력타입, 카테고리, 설명, ID로 실시간 필터링
- 검색 결과 건수 표시 및 초기화 버튼

src/components/items/ItemMasterDataManagement/tabs/MasterFieldTab/index.tsx

@@ -6,12 +6,14 @@
  * - item_fields WHERE section_id IS NULL로 통합
  * - 향후 FieldTab으로 리네임 예정
  */
+import { useState, useMemo } from 'react';
 import type { ItemMasterField } from '@/contexts/ItemMasterContext';
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from '@/components/ui/card';
 import { Button } from '@/components/ui/button';
 import { Badge } from '@/components/ui/badge';
+import { Input } from '@/components/ui/input';
 import { getPresetStyle } from '@/lib/utils/status-config';
-import { Plus, Edit, Trash2 } from 'lucide-react';
+import { Plus, Edit, Trash2, Search, X } from 'lucide-react';
 
 // 입력방식 옵션 (ItemMasterDataManagement에서 사용하는 상수)
 const INPUT_TYPE_OPTIONS = [
@@ -50,6 +52,21 @@ export function MasterFieldTab({
   hasUnsavedChanges: _hasUnsavedChanges,
   pendingChanges: _pendingChanges
 }: MasterFieldTabProps) {
+  const [searchQuery, setSearchQuery] = useState('');
+
+  const filteredFields = useMemo(() => {
+    if (!searchQuery.trim()) return itemMasterFields;
+    const query = searchQuery.trim().toLowerCase();
+    return itemMasterFields.filter(field => {
+      const fieldName = field.field_name?.toLowerCase() || '';
+      const fieldType = INPUT_TYPE_OPTIONS.find(t => t.value === field.field_type)?.label?.toLowerCase() || '';
+      const category = field.category?.toLowerCase() || '';
+      const description = field.description?.toLowerCase() || '';
+      const fieldId = String(field.id);
+      return fieldName.includes(query) || fieldType.includes(query) || category.includes(query) || description.includes(query) || fieldId.includes(query);
+    });
+  }, [itemMasterFields, searchQuery]);
+
   return (
     <Card>
       <CardHeader>
@@ -70,6 +87,25 @@ export function MasterFieldTab({
             <Plus className="h-4 w-4 mr-2" />항목 추가
           </Button>
         </div>
+        {itemMasterFields.length > 0 && (
+          <div className="relative mt-3">
+            <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
+            <Input
+              placeholder="항목명, 입력타입, 카테고리, ID로 검색..."
+              value={searchQuery}
+              onChange={(e) => setSearchQuery(e.target.value)}
+              className="pl-9 pr-9"
+            />
+            {searchQuery && (
+              <button
+                onClick={() => setSearchQuery('')}
+                className="absolute right-3 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
+              >
+                <X className="h-4 w-4" />
+              </button>
+            )}
+          </div>
+        )}
       </CardHeader>
       <CardContent>
         {itemMasterFields.length === 0 ? (
@@ -81,7 +117,17 @@ export function MasterFieldTab({
           </div>
         ) : (
           <div className="space-y-2">
-            {itemMasterFields.map((field, index) => (
+            {searchQuery && (
+              <p className="text-sm text-muted-foreground mb-2">
+                {filteredFields.length}건 검색됨 (전체 {itemMasterFields.length}건)
+              </p>
+            )}
+            {filteredFields.length === 0 && searchQuery ? (
+              <div className="text-center py-8">
+                <p className="text-muted-foreground">"{searchQuery}"에 대한 검색 결과가 없습니다</p>
+              </div>
+            ) : null}
+            {filteredFields.map((field, index) => (
               <div key={`masterfield-${field.id}-${index}`} className="flex items-center justify-between p-4 border rounded hover:bg-gray-50 transition-colors">
                 <div className="flex-1">
                   <div className="flex items-center gap-2">