feat: Implement entity join functionality in V2Repeater and configuration panel

- Added support for entity joins in the V2Repeater component, allowing for automatic resolution of foreign key references to display data from related tables.
- Introduced a new `resolveEntityJoins` function to handle the fetching and mapping of reference data based on configured entity joins.
- Enhanced the V2RepeaterConfigPanel to manage entity join configurations, including loading available columns and toggling join settings.
- Updated the data handling logic to incorporate mapping rules for incoming data, ensuring that only necessary fields are retained during processing.
- Improved user experience by providing clear logging and feedback during entity join resolution and data mapping operations.

frontend/lib/registry/components/modal-repeater-table/ItemSelectionModal.tsx

@@ -305,12 +305,26 @@ export function ItemSelectionModal({
     onOpenChange(false);
   };
 
-  // 이미 추가된 항목인지 확인
+  // 이미 추가된 항목인지 확인 (매핑된 데이터의 _sourceData도 검사)
   const isAlreadyAdded = (item: any): boolean => {
-    if (!uniqueField) return false;
-    return alreadySelected.some(
-      (selected) => selected[uniqueField] === item[uniqueField]
-    );
+    const checkField = uniqueField || "id";
+    const itemValue = item[checkField];
+    if (itemValue === undefined || itemValue === null) return false;
+    const strItemValue = String(itemValue);
+
+    return alreadySelected.some((selected) => {
+      // _sourceData 우선 확인 (DB 로드 항목의 참조 ID가 매핑되어 있음)
+      const sourceValue = selected._sourceData?.[checkField];
+      if (sourceValue !== undefined && sourceValue !== null && String(sourceValue) === strItemValue) {
+        return true;
+      }
+      // _sourceData에 없으면 직접 필드 비교 (동일 필드명인 경우)
+      const directValue = selected[checkField];
+      if (directValue !== undefined && directValue !== null && String(directValue) === strItemValue) {
+        return true;
+      }
+      return false;
+    });
   };
 
   // 이미 추가된 항목 제외한 결과 필터링

frontend/lib/registry/components/split-panel-layout2/SplitPanelLayout2Component.tsx

@@ -642,6 +642,12 @@ export const SplitPanelLayout2Component: React.FC<SplitPanelLayout2ComponentProp
       }
     }
 
+    // 메인 레코드 ID 전달 (분할패널에서는 좌측 선택 항목이 메인 레코드)
+    const leftPkColumn = config.leftPanel?.primaryKeyColumn || "id";
+    if (selectedLeftItem?.[leftPkColumn]) {
+      initialData._mainRecordId = selectedLeftItem[leftPkColumn];
+    }
+
     // EditModal 열기 이벤트 발생
     const event = new CustomEvent("openEditModal", {
       detail: {
@@ -662,6 +668,7 @@ export const SplitPanelLayout2Component: React.FC<SplitPanelLayout2ComponentProp
   }, [
     config.rightPanel?.addModalScreenId,
     config.rightPanel?.addButtonLabel,
+    config.leftPanel?.primaryKeyColumn,
     config.dataTransferFields,
     selectedLeftItem,
     loadRightData,
@@ -718,6 +725,12 @@ export const SplitPanelLayout2Component: React.FC<SplitPanelLayout2ComponentProp
         }
       }
 
+      // 메인 레코드 ID 전달 (디테일 레코드의 id와 구분)
+      const editItemLeftPkColumn = config.leftPanel?.primaryKeyColumn || "id";
+      if (selectedLeftItem?.[editItemLeftPkColumn]) {
+        editData._mainRecordId = selectedLeftItem[editItemLeftPkColumn];
+      }
+
       // EditModal 열기 이벤트 발생 (수정 모드)
       const event = new CustomEvent("openEditModal", {
         detail: {
@@ -737,7 +750,7 @@ export const SplitPanelLayout2Component: React.FC<SplitPanelLayout2ComponentProp
       window.dispatchEvent(event);
       console.log("[SplitPanelLayout2] 우측 수정 모달 열기:", editData);
     },
-    [config.rightPanel?.editModalScreenId, config.rightPanel?.addModalScreenId, config.rightPanel?.mainTableForEdit, selectedLeftItem, loadRightData, loadLeftData],
+    [config.rightPanel?.editModalScreenId, config.rightPanel?.addModalScreenId, config.rightPanel?.mainTableForEdit, config.leftPanel?.primaryKeyColumn, selectedLeftItem, loadRightData, loadLeftData],
   );
 
   // 좌측 패널 수정 버튼 클릭
@@ -896,6 +909,12 @@ export const SplitPanelLayout2Component: React.FC<SplitPanelLayout2ComponentProp
               }
             }
 
+            // 메인 레코드 ID 전달 (분할패널에서는 좌측 선택 항목이 메인 레코드)
+            const addLeftPkColumn = config.leftPanel?.primaryKeyColumn || "id";
+            if (selectedLeftItem?.[addLeftPkColumn]) {
+              initialData._mainRecordId = selectedLeftItem[addLeftPkColumn];
+            }
+
             const event = new CustomEvent("openEditModal", {
               detail: {
                 screenId: btn.modalScreenId,
@@ -929,12 +948,19 @@ export const SplitPanelLayout2Component: React.FC<SplitPanelLayout2ComponentProp
                 return;
               }
 
+              // 메인 레코드 ID 전달 (디테일 레코드의 id와 구분)
+              const editLeftPkColumn = config.leftPanel?.primaryKeyColumn || "id";
+              const editData = { ...item };
+              if (selectedLeftItem?.[editLeftPkColumn]) {
+                editData._mainRecordId = selectedLeftItem[editLeftPkColumn];
+              }
+
               const event = new CustomEvent("openEditModal", {
                 detail: {
                   screenId: modalScreenId,
                   title: btn.label || "수정",
                   modalSize: "lg",
-                  editData: item,
+                  editData,
                   isCreateMode: false,
                   onSave: () => {
                     if (selectedLeftItem) {

frontend/lib/registry/components/universal-form-modal/TableSectionRenderer.tsx

@@ -2132,6 +2132,101 @@ export function TableSectionRenderer({
     return Object.values(conditionalTableData).reduce((sum, data) => sum + data.length, 0);
   }, [conditionalTableData]);
 
+  // 조건부 테이블: 모달 중복 체크용 alreadySelected 구성
+  // DB에서 로드된 항목은 _sourceData가 없으므로 참조 ID 필드를 기반으로 _sourceData를 생성
+  const conditionalAlreadySelected = useMemo(() => {
+    const allItems = Object.values(conditionalTableData).flat();
+    if (allItems.length === 0) return allItems;
+
+    // 참조 ID 필드 탐색 (소스 테이블의 id를 저장하는 디테일 테이블 컬럼)
+    const referenceIdField = (tableConfig.columns || [])
+      .map((col) => col.saveConfig?.referenceDisplay?.referenceIdField)
+      .find(Boolean)
+      || (tableConfig.columns || [])
+        .map((col) => (col as any).dynamicSelectOptions?.rowSelectionMode?.targetIdField)
+        .find(Boolean);
+
+    // sourceField 매핑 수집 (소스 테이블 필드 → 디테일 테이블 필드)
+    const sourceFieldMap: Record<string, string> = {};
+    for (const col of tableConfig.columns || []) {
+      if (col.sourceField && col.sourceField !== col.field) {
+        sourceFieldMap[col.sourceField] = col.field;
+      }
+    }
+
+    return allItems.map((item) => {
+      if (item._sourceData) return item;
+
+      // DB에서 로드된 항목: _sourceData 재구성
+      const sourceData: any = {};
+
+      // 참조 ID 필드가 있으면 소스 테이블의 id로 매핑
+      if (referenceIdField && item[referenceIdField] !== undefined) {
+        sourceData.id = item[referenceIdField];
+      }
+
+      // sourceField 매핑을 역으로 적용 (디테일 필드 → 소스 필드)
+      for (const [srcField, detailField] of Object.entries(sourceFieldMap)) {
+        if (item[detailField] !== undefined) {
+          sourceData[srcField] = item[detailField];
+        }
+      }
+
+      // 디테일 테이블의 필드도 소스 데이터에 포함 (동일 필드명인 경우)
+      for (const col of tableConfig.columns || []) {
+        if (!col.sourceField && item[col.field] !== undefined) {
+          sourceData[col.field] = item[col.field];
+        }
+      }
+
+      return Object.keys(sourceData).length > 0
+        ? { ...item, _sourceData: sourceData }
+        : item;
+    });
+  }, [conditionalTableData, tableConfig.columns]);
+
+  // 일반 테이블: 모달 중복 체크용 alreadySelected 구성 (DB 로드 항목 대응)
+  const normalAlreadySelected = useMemo(() => {
+    if (tableData.length === 0) return tableData;
+
+    const referenceIdField = (tableConfig.columns || [])
+      .map((col) => col.saveConfig?.referenceDisplay?.referenceIdField)
+      .find(Boolean)
+      || (tableConfig.columns || [])
+        .map((col) => (col as any).dynamicSelectOptions?.rowSelectionMode?.targetIdField)
+        .find(Boolean);
+
+    const sourceFieldMap: Record<string, string> = {};
+    for (const col of tableConfig.columns || []) {
+      if (col.sourceField && col.sourceField !== col.field) {
+        sourceFieldMap[col.sourceField] = col.field;
+      }
+    }
+
+    return tableData.map((item) => {
+      if (item._sourceData) return item;
+
+      const sourceData: any = {};
+      if (referenceIdField && item[referenceIdField] !== undefined) {
+        sourceData.id = item[referenceIdField];
+      }
+      for (const [srcField, detailField] of Object.entries(sourceFieldMap)) {
+        if (item[detailField] !== undefined) {
+          sourceData[srcField] = item[detailField];
+        }
+      }
+      for (const col of tableConfig.columns || []) {
+        if (!col.sourceField && item[col.field] !== undefined) {
+          sourceData[col.field] = item[col.field];
+        }
+      }
+
+      return Object.keys(sourceData).length > 0
+        ? { ...item, _sourceData: sourceData }
+        : item;
+    });
+  }, [tableData, tableConfig.columns]);
+
   // ============================================
   // 조건부 테이블 렌더링
   // ============================================
@@ -2449,7 +2544,7 @@ export function TableSectionRenderer({
           multiSelect={multiSelect}
           filterCondition={conditionalFilterCondition}
           modalTitle={`${effectiveOptions.find((o) => o.value === modalCondition)?.label || modalCondition} - ${modalTitle}`}
-          alreadySelected={Object.values(conditionalTableData).flat()}
+          alreadySelected={conditionalAlreadySelected}
           uniqueField={tableConfig.saveConfig?.uniqueField}
           onSelect={handleConditionalAddItems}
           columnLabels={columnLabels}
@@ -2560,7 +2655,7 @@ export function TableSectionRenderer({
         multiSelect={multiSelect}
         filterCondition={baseFilterCondition}
         modalTitle={modalTitle}
-        alreadySelected={tableData}
+        alreadySelected={normalAlreadySelected}
         uniqueField={tableConfig.saveConfig?.uniqueField}
         onSelect={handleAddItems}
         columnLabels={columnLabels}

frontend/lib/registry/components/universal-form-modal/UniversalFormModalComponent.tsx

@@ -468,6 +468,11 @@ export function UniversalFormModalComponent({
         console.log(`[UniversalFormModal] 원본 그룹 데이터 병합: ${originalGroupedData.length}개`);
       }
 
+      // 분할패널에서 전달한 메인 레코드 ID 전달
+      if (latestFormData._mainRecordId) {
+        event.detail.formData._mainRecordId = latestFormData._mainRecordId;
+      }
+
       // 🆕 부모 formData의 중첩 객체(modalKey)도 최신 데이터로 업데이트
       // onChange(setTimeout)가 아직 부모에 전파되지 않았을 수 있으므로 직접 업데이트
       for (const parentKey of Object.keys(event.detail.formData)) {
@@ -993,6 +998,11 @@ export function UniversalFormModalComponent({
       }
     }
 
+    // 분할패널에서 전달한 메인 레코드 ID 보존
+    if (effectiveInitialData?._mainRecordId) {
+      newFormData._mainRecordId = effectiveInitialData._mainRecordId;
+    }
+
     setFormData(newFormData);
     formDataRef.current = newFormData;
     setRepeatSections(newRepeatSections);

frontend/lib/registry/components/v2-repeater/V2RepeaterRenderer.tsx

@@ -44,9 +44,11 @@ const V2RepeaterRenderer: React.FC<V2RepeaterRendererProps> = ({
     console.log("📋 V2RepeaterRenderer config 추출:", {
       hasComponentConfig: !!component?.componentConfig,
       hasConfig: !!component?.config,
+      hasOverrides: !!(component as any)?.overrides,
       useCustomTable: componentConfig.useCustomTable,
       mainTableName: componentConfig.mainTableName,
       foreignKeyColumn: componentConfig.foreignKeyColumn,
+      entityJoins: componentConfig.entityJoins,
     });
     
     return {