Add BOM Copy Functionality to BOM Management

- Introduced a new API endpoint to copy a BOM tree to multiple target items, allowing for efficient duplication of BOM structures.
- Implemented payload validation to ensure correct data format and integrity during the copy process.
- Added a modal in the frontend for managing the BOM copy operation, including options for conflict resolution and progress tracking.
- Enhanced the BOM service with necessary logic for handling BOM copies, including versioning and error handling.

(TASK: ERP-028)

backend-node/src/controllers/bomController.ts

@@ -143,6 +143,73 @@ export async function initializeBomVersion(req: Request, res: Response) {
   }
 }
 
+// ─── BOM 복사 (TASK:ERP-028) ─────────────────────────
+
+/**
+ * POST /bom/:bomId/copy-to-items
+ * 기준 BOM의 트리(편집본)를 대상 품목 N개에 복제
+ * - conflictStrategy = "skip": 대상 품목에 BOM 있으면 skipped[]
+ * - conflictStrategy = "new_version": 대상 품목 BOM에 새 draft 버전 추가 (없으면 새 BOM 생성)
+ */
+export async function copyBomToItems(req: Request, res: Response) {
+  try {
+    const { bomId } = req.params;
+    const companyCode = (req as any).user?.companyCode || "*";
+    const userId = (req as any).user?.userName || (req as any).user?.userId || "";
+
+    const { targetItemIds, conflictStrategy, editedTree } = req.body || {};
+
+    // ─── 페이로드 검증 ─────────────────────
+    if (!Array.isArray(targetItemIds) || targetItemIds.length === 0) {
+      res.status(400).json({ success: false, message: "targetItemIds는 1개 이상의 배열이어야 합니다" });
+      return;
+    }
+    if (conflictStrategy !== "skip" && conflictStrategy !== "new_version") {
+      res.status(400).json({ success: false, message: "conflictStrategy는 'skip' 또는 'new_version'이어야 합니다" });
+      return;
+    }
+    if (!Array.isArray(editedTree) || editedTree.length === 0) {
+      res.status(400).json({ success: false, message: "editedTree는 1개 이상의 노드 배열이어야 합니다" });
+      return;
+    }
+
+    // 트리 노드 필수 필드 검증
+    for (const n of editedTree) {
+      if (!n || typeof n !== "object") {
+        res.status(400).json({ success: false, message: "editedTree 노드는 객체여야 합니다" });
+        return;
+      }
+      if (!n.tempId) {
+        res.status(400).json({ success: false, message: "editedTree 각 노드에는 tempId가 필요합니다" });
+        return;
+      }
+      if (!n.childItemId) {
+        res.status(400).json({ success: false, message: `노드 ${n.tempId}: childItemId가 필요합니다` });
+        return;
+      }
+      const qty = Number(n.quantity);
+      if (!Number.isFinite(qty) || qty <= 0) {
+        res.status(400).json({ success: false, message: `노드 ${n.tempId}: quantity는 0보다 커야 합니다` });
+        return;
+      }
+    }
+
+    const data = await bomService.copyBomToItems({
+      sourceBomId: bomId,
+      companyCode,
+      userId,
+      targetItemIds,
+      conflictStrategy,
+      editedTree,
+    });
+
+    res.json({ success: true, data });
+  } catch (error: any) {
+    logger.error("BOM 복사 실패", { error: error.message });
+    res.status(500).json({ success: false, message: error.message });
+  }
+}
+
 // ─── BOM 엑셀 업로드/다운로드 ─────────────────────────
 
 export async function createBomFromExcel(req: Request, res: Response) {