[Bug] File selection via "@" mention doesn't highlight selected state (after the new "clickable" feature was implemented)

Bug Description
The new clickable file names when using "@" do not highlight when selected. This makes it impossible to know which file you select to include in the prompt. And clicking them just opens the file. This is a real issue.

Environment Info

• Platform: win32
• Terminal: pycharm
• Version: 2.0.57
• Feedback ID: dcaa3b5f-06a2-4ac3-9888-6ef9fa388d6d

Notice all the files are highlighted. When I use the mouse cursor to select one, there is no way to tell which one is selected.

<img width="963" height="427" alt="Image" src="https://github.com/user-attachments/assets/0ef80ad8-5d28-4895-af34-ba4ac41a79c5" />