fix(render): harden portal exit handoff

src/AcDream.Core/World/TeleportAnimSequencer.cs

@@ -53,7 +53,13 @@ public sealed class TeleportAnimSequencer
     public const int TunnelEndFrame = 120;
     public const float ExitWindowLow = FadeTime + 0.1f;
     public const float ExitWindowHigh = FadeTime + 0.3f;
-    private const short LastVisibleOutgoingAnimationLevel = 1022;
+    // The retail viewport swap happens before the finite portal mesh reaches
+    // the final near-180-degree samples. Full-width 1280x720 captures establish
+    // level 1001 as the last radial field that covers the viewport; 1006 starts
+    // exposing the mesh perimeter and 1013 can leave its complete faceted rim
+    // on screen. Keep the cutoff in the quantized retail table domain so
+    // refresh rate cannot move the swap.
+    internal const short LastVisibleOutgoingAnimationLevel = 1001;
 
     // UIGlobals::Init @ 0x004EE470. Retail integrates 100 integer sine
     // samples into a 0..1024 easing table.
@@ -102,10 +108,18 @@ public sealed class TeleportAnimSequencer
     /// Advance the machine by <paramref name="dt"/> seconds.
     /// <paramref name="worldReady"/> = the complete destination-load barrier is
     /// satisfied (Near-tier render meshes/textures plus collision residency).
+    /// <paramref name="holdInTunnel"/> is diagnostic apparatus: when true the
+    /// machine observes readiness but withholds the <c>Place</c> edge and stays
+    /// in the stable tunnel state. The default is false and retail behavior is
+    /// unchanged.
     /// Returns the current snapshot + edge-triggered events fired THIS tick.
     /// </summary>
     public (TeleportAnimSnapshot snapshot, IReadOnlyList<TeleportAnimEvent> events)
-        Tick(float dt, bool worldReady, int tunnelAnimationFrame = 72)
+        Tick(
+            float dt,
+            bool worldReady,
+            int tunnelAnimationFrame = 72,
+            bool holdInTunnel = false)
     {
         var evts = new List<TeleportAnimEvent>();
 
@@ -133,7 +147,7 @@ public sealed class TeleportAnimSequencer
 
             case TeleportAnimState.Tunnel:
                 // Hold here until worldReady (EndTeleportAnimation analogue).
-                if (worldReady)
+                if (worldReady && !holdInTunnel)
                 {
                     evts.Add(TeleportAnimEvent.Place);
                     Advance(TeleportAnimState.TunnelContinue, enterTunnel: false);
@@ -183,10 +197,9 @@ public sealed class TeleportAnimSequencer
 
     /// <summary>
     /// Retire an outgoing viewport before the first quantized projection that
-    /// exposes the finite tunnel boundary. Retail's whole-frame black clear and
-    /// frame-paced D3D presentation show level 1022 as the last tunnel sample;
-    /// paired captures show no 1023/1024 portal frame before the world swap.
-    /// An uncapped modern loop can otherwise publish those sub-20 ms samples
+    /// exposes the finite tunnel boundary. Full-width captures show 1001 as
+    /// the last covered sample and 1006 as the first divergent faceted edge.
+    /// An uncapped modern loop can otherwise publish those terminal samples
     /// and let the desktop compositor hold one for a complete display refresh.
     /// </summary>
     private bool OutgoingViewportReachedTerminalProjection()