[feat]: Item Master 데이터 관리 기능 구현 및 타입 에러 수정

- ItemMasterDataManagement 컴포넌트 구조화 (tabs, dialogs, components 분리)
- HierarchyTab 타입 에러 수정 (BOMItem section_id, updated_at 추가)
- API 클라이언트 구현 (item-master.ts, 13개 엔드포인트)
- ItemMasterContext 구현 (상태 관리 및 데이터 흐름)
- 백엔드 요구사항 문서 작성 (CORS 설정, API 스펙 등)
- SSR 호환성 수정 (navigator API typeof window 체크)
- 미사용 변수 ESLint 에러 해결
- Context 리팩토링 (AuthContext, RootProvider 추가)
- API 유틸리티 추가 (error-handler, logger, transformers)

🤖 Generated with Claude Code

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

src/components/items/ItemMasterDataManagement/dialogs/ColumnDialog.tsx

@@ -0,0 +1,106 @@
+'use client';
+
+import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle } from '@/components/ui/dialog';
+import { Button } from '@/components/ui/button';
+import { Label } from '@/components/ui/label';
+import { Input } from '@/components/ui/input';
+import { toast } from 'sonner';
+
+interface ColumnDialogProps {
+  isColumnDialogOpen: boolean;
+  setIsColumnDialogOpen: (open: boolean) => void;
+  editingColumnId: string | null;
+  setEditingColumnId: (id: string | null) => void;
+  columnName: string;
+  setColumnName: (name: string) => void;
+  columnKey: string;
+  setColumnKey: (key: string) => void;
+  textboxColumns: Array<{ id: string; name: string; key: string }>;
+  setTextboxColumns: React.Dispatch<React.SetStateAction<Array<{ id: string; name: string; key: string }>>>;
+}
+
+export function ColumnDialog({
+  isColumnDialogOpen,
+  setIsColumnDialogOpen,
+  editingColumnId,
+  setEditingColumnId,
+  columnName,
+  setColumnName,
+  columnKey,
+  setColumnKey,
+  textboxColumns,
+  setTextboxColumns,
+}: ColumnDialogProps) {
+  const handleSubmit = () => {
+    if (!columnName.trim() || !columnKey.trim()) {
+      return toast.error('모든 필드를 입력해주세요');
+    }
+
+    if (editingColumnId) {
+      // 수정
+      setTextboxColumns(prev => prev.map(col =>
+        col.id === editingColumnId
+          ? { ...col, name: columnName, key: columnKey }
+          : col
+      ));
+      toast.success('컬럼이 수정되었습니다');
+    } else {
+      // 추가
+      setTextboxColumns(prev => [...prev, {
+        id: `col-${Date.now()}`,
+        name: columnName,
+        key: columnKey
+      }]);
+      toast.success('컬럼이 추가되었습니다');
+    }
+
+    setIsColumnDialogOpen(false);
+    setEditingColumnId(null);
+    setColumnName('');
+    setColumnKey('');
+  };
+
+  return (
+    <Dialog open={isColumnDialogOpen} onOpenChange={(open) => {
+      setIsColumnDialogOpen(open);
+      if (!open) {
+        setEditingColumnId(null);
+        setColumnName('');
+        setColumnKey('');
+      }
+    }}>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>{editingColumnId ? '컬럼 수정' : '컬럼 추가'}</DialogTitle>
+          <DialogDescription>
+            텍스트박스에 추가할 컬럼 정보를 입력하세요
+          </DialogDescription>
+        </DialogHeader>
+        <div className="space-y-4">
+          <div>
+            <Label>컬럼명 *</Label>
+            <Input
+              value={columnName}
+              onChange={(e) => setColumnName(e.target.value)}
+              placeholder="예: 가로"
+            />
+          </div>
+          <div>
+            <Label>컬럼 키 *</Label>
+            <Input
+              value={columnKey}
+              onChange={(e) => setColumnKey(e.target.value)}
+              placeholder="예: width"
+            />
+          </div>
+        </div>
+        <DialogFooter>
+          <Button variant="outline" onClick={() => setIsColumnDialogOpen(false)}>취소</Button>
+          <Button onClick={handleSubmit}>
+            {editingColumnId ? '수정' : '추가'}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  );
+}