Feat: Support PaddleOCR-VL-1.5 interface (#12819)

### What problem does this PR solve?

This PR adds support to PaddleOCR-VL-1.5 interface to the PaddleOCR PDF
Parser.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

web/src/components/paddleocr-options-form-field.tsx

@@ -83,7 +83,7 @@ export function PaddleOCROptionsFormField({
       >
         {(field) => (
           <RAGFlowSelect
-            value={field.value || 'PaddleOCR-VL'}
+            value={field.value || undefined}
             onChange={field.onChange}
             options={algorithmOptions}
             placeholder={t('common.selectPlaceholder', 'Select value')}