fix overlay :)

src/core/hle/service/am/display_layer_manager.cpp

@@ -158,10 +158,14 @@ void DisplayLayerManager::SetWindowVisibility(bool visible) {
 
     if (m_manager_display_service) {
         if (m_system_shared_layer_id) {
+            LOG_INFO(Service_VI, "DLM: SetWindowVisibility shared_layer={} visible={} applet_id={}",
+                     m_system_shared_layer_id, m_visible, static_cast<u32>(m_applet_id));
             m_manager_display_service->SetLayerVisibility(m_visible, m_system_shared_layer_id);
         }
 
         for (const auto layer_id : m_managed_display_layers) {
+            LOG_INFO(Service_VI, "DLM: SetWindowVisibility managed_layer={} visible={} applet_id={}",
+                     layer_id, m_visible, static_cast<u32>(m_applet_id));
             m_manager_display_service->SetLayerVisibility(m_visible, layer_id);
         }
     }

src/core/hle/service/am/window_system.cpp

@@ -312,10 +312,22 @@ void WindowSystem::UpdateAppletStateLocked(Applet* applet, bool is_foreground) {
     }();
 
     // Update visibility state.
-    applet->display_layer_manager.SetWindowVisibility(is_foreground && applet->window_visible);
+    // Overlay applets should always be visible when window_visible is true, regardless of foreground state
+    const bool should_be_visible = (applet->applet_id == AppletId::OverlayDisplay)
+                                     ? applet->window_visible
+                                     : (is_foreground && applet->window_visible);
+    if (applet->applet_id == AppletId::OverlayDisplay) {
+        LOG_INFO(Service_AM, "WindowSystem: Overlay visibility update - window_visible={} should_be_visible={} is_foreground={}",
+                 applet->window_visible, should_be_visible, is_foreground);
+    }
+    applet->display_layer_manager.SetWindowVisibility(should_be_visible);
 
     // Update interactibility state.
-    applet->SetInteractibleLocked(is_foreground && applet->window_visible);
+    // Overlay applets should be interactible when visible, as they need to handle input (e.g. home button)
+    const bool should_be_interactible = (applet->applet_id == AppletId::OverlayDisplay)
+                                          ? applet->window_visible
+                                          : (is_foreground && applet->window_visible);
+    applet->SetInteractibleLocked(should_be_interactible);
 
     // Update focus state and suspension.
     const bool is_obscured = has_obscuring_child_applets || !applet->window_visible;

src/core/hle/service/nvnflinger/hardware_composer.cpp

@@ -130,7 +130,7 @@ u32 HardwareComposer::ComposeLocked(f32* out_speed_scale, Display& display,
     if (has_acquired_buffer && !composition_stack.empty()) {
         // Sort back-to-front: lower z first, higher z last so top-most draws last (on top).
         std::stable_sort(composition_stack.begin(), composition_stack.end(),
-                         [&](const HwcLayer& l, const HwcLayer& r) { return l.z_index > r.z_index; });
+                         [&](const HwcLayer& l, const HwcLayer& r) { return l.z_index < r.z_index; });
 
         // Composite.
         nvdisp.Composite(composition_stack);