No "Default" Workspace Button

The [Workspaces](https://docs.zen-browser.app/user-manual/workspaces#adding-a-new-workspace) section of the User Manual says to click on the "Default" button in the sidebar to create a new workspace. I don't have that button in my fresh install.

<img width="464" height="785" alt="Image" src="https://github.com/user-attachments/assets/312cbc76-416a-47fc-b87b-df9f665329dd" />