fix: Update segmentation type initialization to support parent-child mode based on document form (#21359)

web/app/components/datasets/create/step-two/index.tsx

@@ -161,7 +161,9 @@ const StepTwo = ({
 
   const isInCreatePage = !datasetId || (datasetId && !currentDataset?.data_source_type)
   const dataSourceType = isInCreatePage ? inCreatePageDataSourceType : currentDataset?.data_source_type
-  const [segmentationType, setSegmentationType] = useState<ProcessMode>(ProcessMode.general)
+  const [segmentationType, setSegmentationType] = useState<ProcessMode>(
+    currentDataset?.doc_form === ChunkingMode.parentChild ? ProcessMode.parentChild : ProcessMode.general,
+  )
   const [segmentIdentifier, doSetSegmentIdentifier] = useState(DEFAULT_SEGMENT_IDENTIFIER)
   const setSegmentIdentifier = useCallback((value: string, canEmpty?: boolean) => {
     doSetSegmentIdentifier(value ? escape(value) : (canEmpty ? '' : DEFAULT_SEGMENT_IDENTIFIER))
@@ -1137,7 +1139,7 @@ const StepTwo = ({
                       const indexForLabel = index + 1
                       return (
                         <PreviewSlice
-                          key={child}
+                          key={`C-${indexForLabel}-${child}`}
                           label={`C-${indexForLabel}`}
                           text={child}
                           tooltip={`Child-chunk-${indexForLabel} · ${child.length} Characters`}