fix(core): fix position of toc in peekview (#8441)

Close [BS-1536](https://linear.app/affine-design/issue/BS-1536/peekview中的toc没有fixed)

packages/frontend/core/src/modules/peek-view/view/doc-preview/doc-peek-view.tsx

@@ -159,15 +159,14 @@ function DocPeekPreviewEditor({
             page={doc.blockSuiteDoc}
             onEditorReady={handleOnEditorReady}
           />
-          <EditorOutlineViewer
-            editor={editorElement}
-            show={mode === 'page'}
-            openOutlinePanel={openOutlinePanel}
-          />
         </Scrollable.Viewport>
-
         <Scrollable.Scrollbar />
       </Scrollable.Root>
+      <EditorOutlineViewer
+        editor={editorElement}
+        show={mode === 'page'}
+        openOutlinePanel={openOutlinePanel}
+      />
     </AffineErrorBoundary>
   );
 }