[enhancement]: Add Model section UI/UX can be confusing, Add Model button doesn't feel intuitive

### Is there an existing issue for this?

- [X] I have searched the existing issues
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### What should this feature add?

Yesterday after checking out the new model manager, I found myself searching for a way to go back to the Add Model section after clicking an entry from the left side of the model manager. The Add Model button didn't feel intuitive.

Some quick ideas:

- One easy fix could be clicking empty space on the left section to deselect that model, restoring the Add Model section on the right.

- Or move the Add Model button to the right section with a less-than sign, acting like a back button: `< Add Model`

- Or just a back button above the right section with a less-than sign: `< Back`