[Bug][TipTap] "You have unsaved changes" state remains after reverting text manually to the original value

## Description

The page enters the "You have unsaved changes" state after a text block is modified. However, if the user manually restores the edited text so that it exactly matches the original value, the page continues to be treated as modified. The unsaved changes state is not cleared even though there are no effective changes left.

## Steps to reproduce

1. Open a document.
2. Click into any text block.
3. Change the text.
4. Manually edit the text back so it matches the original value exactly.

## Actual result

The page continues to display the **"You have unsaved changes"** state, even though there are no effective changes compared to the original state.

## Expected result

When the current text matches the original value again:

* the **"You have unsaved changes"** state should disappear;
* the page should no longer be treated as modified;
* **Revert** / **Approve** actions should not be shown.

https://github.com/user-attachments/assets/19faecfc-5b3b-479c-9e80-c4f7a70f0a08