frontend/components/unified/config-panels/UnifiedRepeaterConfigPanel.tsx

@@ -477,7 +477,36 @@ export const UnifiedRepeaterConfigPanel: React.FC<UnifiedRepeaterConfigPanelProp
           {/* 렌더링 모드 */}
           <div className="space-y-2">
             <Label className="text-xs font-medium">렌더링 모드</Label>
-            <Select value={config.renderMode} onValueChange={(value) => updateConfig({ renderMode: value as any })}>
+            <Select 
+              value={config.renderMode} 
+              onValueChange={(value) => {
+                const newMode = value as any;
+                const currentMode = config.renderMode;
+                
+                // 모달 → 인라인 모드로 변경 시: isSourceDisplay 컬럼 제거 및 모달 설정 초기화
+                if (currentMode === "modal" && newMode === "inline") {
+                  const filteredColumns = config.columns.filter((col) => !col.isSourceDisplay);
+                  updateConfig({ 
+                    renderMode: newMode,
+                    columns: filteredColumns,
+                    dataSource: {
+                      ...config.dataSource,
+                      sourceTable: undefined,
+                      foreignKey: undefined,
+                      referenceKey: undefined,
+                      displayColumn: undefined,
+                    },
+                    modal: {
+                      ...config.modal,
+                      searchFields: [],
+                      sourceDisplayColumns: [],
+                    },
+                  });
+                } else {
+                  updateConfig({ renderMode: newMode });
+                }
+              }}
+            >
               <SelectTrigger className="h-8 text-xs">
                 <SelectValue placeholder="모드 선택" />
               </SelectTrigger>