fix: .knowledgebase folder can be deleted bug and change "Add file to knowledge base" to "Link file to knowledge base" bug (#786)

### What problem does this PR solve?
fix: .knowledgebase folder can be deleted bug 
fix: change "Add file to knowledge base" to "Link file to knowledge
base" bug
#783 #784

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/file-manager/hooks.ts

@@ -14,6 +14,7 @@ import { useGetPagination, useSetPagination } from '@/hooks/logicHooks';
 import { useOneNamespaceEffectsLoading } from '@/hooks/storeHooks';
 import { IFile } from '@/interfaces/database/file-manager';
 import { PaginationProps } from 'antd';
+import { TableRowSelection } from 'antd/es/table/interface';
 import { UploadFile } from 'antd/lib';
 import { useCallback, useEffect, useMemo, useState } from 'react';
 import { useDispatch, useNavigate, useSearchParams, useSelector } from 'umi';
@@ -93,8 +94,11 @@ export const useHandleSearchChange = () => {
 export const useGetRowSelection = () => {
   const [selectedRowKeys, setSelectedRowKeys] = useState<React.Key[]>([]);
 
-  const rowSelection = {
+  const rowSelection: TableRowSelection<IFile> = {
     selectedRowKeys,
+    getCheckboxProps: (record) => {
+      return { disabled: record.source_type === 'knowledgebase' };
+    },
     onChange: (newSelectedRowKeys: React.Key[]) => {
       setSelectedRowKeys(newSelectedRowKeys);
     },