Enhance Outbound and Excel Service Functionality

- Added `inventory_unit` to the item selection query in the outbound controller to improve data retrieval.
- Updated the multi-table Excel service to exclude overlapping headers between parent and child levels, ensuring accurate data insertion.
- Introduced new category combobox components for better user interaction in the supplied item page.
- Enhanced the inbound-outbound page to correctly map user IDs, including super admin handling for user information retrieval.

(TASK: ERP-XXX)

backend-node/src/controllers/outboundController.ts

@@ -740,7 +740,7 @@ export async function getItems(req: AuthenticatedRequest, res: Response) {
 		const pool = getPool();
 		const result = await pool.query(
 			`SELECT
-        id, item_number, item_name, size AS spec, material, unit,
+        id, item_number, item_name, size AS spec, material, unit, inventory_unit,
         COALESCE(width::text, '') AS width,
         COALESCE(height::text, '') AS height,
         COALESCE(thickness::text, '') AS thickness,

backend-node/src/services/multiTableExcelService.ts

@@ -156,6 +156,17 @@ class MultiTableExcelService {
         () => new Map()
       );
 
+      // 자식 단계 빈 데이터 판정에 부모와 겹치는 헤더는 제외해야 한다.
+      // (예: customer_mng/customer_item_mapping 둘 다 '상태','비고' 헤더를 가지면
+      //  부모용으로 입력한 값이 자식에도 잘못 들어가 자식 INSERT가 시도된다.)
+      const ownHeadersPerLevel: Set<string>[] = activeLevels.map((lv, i) => {
+        const headers = new Set(lv.columns.map((c) => c.excelHeader));
+        for (let j = 0; j < i; j++) {
+          for (const c of activeLevels[j].columns) headers.delete(c.excelHeader);
+        }
+        return headers;
+      });
+
       for (let rowIdx = 0; rowIdx < rows.length; rowIdx++) {
         const row = rows[rowIdx];
 
@@ -178,8 +189,19 @@ class MultiTableExcelService {
               }
             }
 
-            const hasAnyData = Object.keys(levelData).length > 0;
-            if (!hasAnyData && lvlIdx > 0) {
+            // 자식 레벨은 '부모와 겹치지 않는 고유 헤더'에 값이 있을 때만 INSERT 진행
+            const ownHeaders = ownHeadersPerLevel[lvlIdx];
+            const hasOwnData =
+              lvlIdx === 0
+                ? Object.keys(levelData).length > 0
+                : level.columns.some(
+                    (c) =>
+                      ownHeaders.has(c.excelHeader) &&
+                      levelData[c.dbColumn] !== undefined &&
+                      levelData[c.dbColumn] !== ""
+                  );
+
+            if (!hasOwnData && lvlIdx > 0) {
               break;
             }