fix: complete retail parity stability pass

tests/AcDream.App.Tests/Rendering/WorldRenderFrameBuilderTests.cs

@@ -300,6 +300,56 @@ public sealed class WorldRenderFrameBuilderTests
         Assert.Contains(hiddenLight, lighting.PointSnapshot);
     }
 
+    [Fact]
+    public void PersistentAtDay_UsesNoonLandscapeLightingWithoutChangingTheSkyClock()
+    {
+        SkyStateProvider sky = SkyStateProvider.Default();
+        var clock = new WorldTimeService(sky);
+        clock.PinnedDayFraction = 0f;
+        var lighting = new LightManager();
+        bool persistentDaylight = true;
+        var environment = new RuntimeWorldFrameEnvironmentPreparation(
+            RuntimeOptions.Parse("test-dat", _ => null),
+            clock,
+            lighting,
+            dispatcher: null,
+            environmentCells: null,
+            lightingUbo: null,
+            new WorldRenderRangeState(4, 12),
+            skyPes: null,
+            persistentDaylight: () => persistentDaylight);
+        WorldCameraFrame camera = CameraFrame(new FlyCamera());
+        WorldRootFrame roots = default;
+        SkyKeyframe midnight = sky.Interpolate(0f);
+        SkyKeyframe noon = sky.Interpolate(0.5f);
+        var foundation = new RenderFrameFoundation(
+            PortalViewportVisible: false,
+            Sky: midnight,
+            Atmosphere: default);
+
+        environment.Prepare(
+            in camera,
+            in roots,
+            in foundation,
+            activeDayGroup: null);
+
+        Assert.Equal(noon.AmbientColor, lighting.CurrentAmbient.AmbientColor);
+        Assert.NotNull(lighting.Sun);
+        Assert.Equal(noon.SunColor, lighting.Sun!.ColorLinear);
+        Assert.Equal(0d, clock.DayFraction, precision: 5);
+
+        persistentDaylight = false;
+        environment.Prepare(
+            in camera,
+            in roots,
+            in foundation,
+            activeDayGroup: null);
+
+        Assert.Equal(midnight.AmbientColor, lighting.CurrentAmbient.AmbientColor);
+        Assert.NotNull(lighting.Sun);
+        Assert.Equal(midnight.SunColor, lighting.Sun!.ColorLinear);
+    }
+
     [Fact]
     public void Environment_preparation_keeps_lighting_snapshot_before_ubo_upload()
     {