[bug] Cannot duplicate a page that has already been duplicated

[spartan-uyen]

Summary: When attempting to duplicate a page that was previously duplicated (e.g., test001-copy), the system throws an error instead of creating a new duplicate.

Steps to Reproduce:

1. Create or select a page named test001.
2. Duplicate it → a new page test001-copy is created.
3. Try duplicating test001-copy.

Actual Result:
An error is shown, and the page is not duplicated.
https://github.com/user-attachments/assets/1b993d5b-e37c-40f7-b9d9-74262a197bde

Expected Result:
A new page should be created with a name like test001-copy-copy or similar without any error.