Revert "fix(render): Phase A8 R3.5 — gate stencil branch on PointInCell containment"

This reverts commit 38d537491f.

src/AcDream.App/Rendering/GameWindow.cs

@@ -7179,29 +7179,7 @@ public sealed class GameWindow : IDisposable
                     animatedIds.Add(k);
             }
 
-            // Phase A8 R3.5 — transition-flicker fix. `cameraInsideCell`
+            if (cameraInsideCell && _indoorStencilPipeline is not null
-            // stays true for ~3 grace frames after the camera physically
-            // exits a cell (see CellVisibility._cellSwitchGraceFrames).
-            // The grace mechanism prevents lighting/sky flicker at the
-            // doorway threshold, but if the stencil pipeline runs during
-            // grace frames it marks/punches at the OLD cell's portal
-            // silhouettes — which are now behind/beside the camera — and
-            // the subsequent IndoorPass + stencil-gated outdoor produce
-            // a brief frame of "walls disappear + buildings under ground"
-            // garbage. Gate the stencil branch on the stricter
-            // `PointInCell` containment check so the pipeline only runs
-            // when the camera is ACTUALLY inside its cell volume; sky /
-            // lighting / depth-clear continue to use `cameraInsideCell`
-            // for their smoother grace-aware behavior.
-            bool cameraReallyInside = visibility?.CameraCell is not null
-                && CellVisibility.PointInCell(camPos, visibility.CameraCell);
-
-            // The `visibility?.CameraCell is not null` repeat is for the
-            // compiler's null-flow analysis: `cameraReallyInside` already
-            // implies it, but flow doesn't propagate through a separate
-            // local. Restating it inside the if condition lets the branch
-            // body use the un-`?`d form without null-forgiving.
-            if (cameraReallyInside && _indoorStencilPipeline is not null
                 && visibility?.CameraCell is not null)
             {
                 if (AcDream.Core.Rendering.RenderingDiagnostics.ProbeVisibilityEnabled)