Missing sidebar

Maybe I'm doing something dumb here, but I lost my left hand sidebar somehow and I can't figure out how to get it back: <img width="674" height="500" alt="Image" src="https://github.com/user-attachments/assets/f1fa7081-cf10-4188-a2f2-23c1072cf864" /> Is this a Swift UI behavior that I toggled on accidentally?