D161 - The GUI is egui on eframe

Status: decided Date: 2026-09-26

orbistoun-gui is an immediate-mode application on egui, through eframe with the wgpu backend. The binary checks for worker mode before any window exists.

Why: its panels - ranked imports, a call tail, registers, a verdict - are replaced wholesale when a run finishes, which is what immediate mode draws well. Presenting a guest frame later is clearer through wgpu than through a webview. The same executable is re-invoked as the worker, so reaching window code there would open a window per launch.

Rejected:

• A webview shell: guest frames would be blitted into it.
• A retained-mode toolkit: effort spent syncing state that is thrown away.