Ψ-W1-T2: disjoint per-mode solo surfaces and a playback-gated mode switch

Solo is cached, cleared and replayed per mode on a real switch only; the switch is refused visibly while the transport runs. The footer segment now routes through the activate actions, so a panel switch finally persists.

src/shell/panel/panel_render.cpp

@@ -112,13 +112,17 @@ void drawFooter(LICE_IBitmap* bmp, int w, int h) {
             const SegmentRect& s = segs[static_cast<std::size_t>(i)];
             const Mode& mode = modes[static_cast<std::size_t>(i)];
             const bool active = mode.id == activeId;
+            // A switch is refused while the transport runs, so an unreachable segment
+            // draws dead rather than inviting a click that would silently do nothing.
+            const bool live = modeSegmentEnabled(active, g_panel.modeSwitchBlocked);
             const InteractionState state =
                 active ? InteractionState::Active
-                       : hoverState(g_panel.hovered, HoverKind::ModeSegment, i);
+                       : (live ? hoverState(g_panel.hovered, HoverKind::ModeSegment, i)
+                               : InteractionState::Disabled);
             fillSurface(bmp, KitBox{s.x, s.y, s.width, s.height}, Role::BgCell, state);
             LICE_DrawRect(bmp, s.x, s.y, s.width, s.height,
                           toLice(roleColor(Role::LineHairline)), 1.0f, 0);
-            const Role tr = active ? Role::BgBase : Role::TextPrimary;
+            const Role tr = active ? Role::BgBase : (live ? Role::TextPrimary : Role::TextDim);
             kitText(bmp, KitBox{s.x, s.y, s.width, s.height}, mode.displayName.c_str(),
                     Font::Label, tr, Align::Center);
         }