fix: split view focus (#11217)

# After:

https://github.com/user-attachments/assets/990d500d-2da7-488e-ac32-dd7bd229f896

# Before:

https://github.com/user-attachments/assets/6676766a-c76a-414b-a35e-53d2cda10c24

tests/blocksuite/e2e/clipboard/list.spec.ts

@@ -481,6 +481,7 @@ test(scoped`copy when text note active in edgeless`, async ({ page }) => {
 
   await activeNoteInEdgeless(page, ids.noteId);
   await waitForInlineEditorStateUpdated(page);
+  await focusRichText(page);
   await setInlineRangeInSelectedRichText(page, 0, 4);
   await copyByKeyboard(page);
   await pressArrowRight(page);