Bug: Demoui forcibly hides cursor and ignores pano menu state

[pivotman319-owo]

Describe the bug

Invoking the demo viewer UI will force the cursor to always be hidden in Panorama, regardless of the main menu state.

p2ce_2026-01-05_01-22-24.mp4

Repro'd on p2ce campaign test branch.

To Reproduce

1. Invoke demoui

Issue Map

Not Applicable

Expected Behavior

Cursor should always show up in UI

Operating System

No response

[JJL772]

everything vgui related doesn't play so well with panorama. I think we intend to replace demoui with imgui at some point (should be a relatively simple task tbh)