The toolbar button next to Export is now a two-state switch: both
labels are visible and the filled half is the current view, so a
diagram that opens in 2D shows "2D" and one click flips it to 3D. The
dropdown is gone; nothing is greyed out and no menu stays open after a
choice.
The 3D-only controls moved to Archify's bottom-right dock beside PATH
and LENS: STACK (levels by kind, on or off), TOP (from above), and the
zoom stepper's middle button reads RESET while 3D is on, instead of a
2D zoom level that meant nothing there.