Toolbar controls the viewer does not offer, hidden through the same EditorUI keys a host
would use. Tools first: the viewer has no path or grab tool and nothing to select between,
so the three tool buttons Toolbar always builds are hidden rather than made conditional —
that keeps one Toolbar, which is the whole point of Option B.
Toolbar controls the viewer does not offer, hidden through the same EditorUI keys a host would use. Tools first: the viewer has no path or grab tool and nothing to select between, so the three tool buttons Toolbar always builds are hidden rather than made conditional — that keeps one Toolbar, which is the whole point of Option B.