fix(render): harden portal exit handoff

src/AcDream.App/Rendering/PortalTunnelPresentation.cs

@@ -1,6 +1,7 @@
 using System.Numerics;
 using AcDream.App.Rendering.Gpu;
 using AcDream.App.Rendering.Wb;
+using AcDream.App.Streaming;
 using AcDream.App.UI;
 using AcDream.Content.Vfx;
 using AcDream.Core.Lighting;
@@ -96,6 +97,7 @@ public sealed class PortalTunnelPresentation : IDisposable
     private float _rotationEndAngle;
     private float _rotationCurrentAngle;
     private bool _waitCueVisible;
+    private bool _probeFreezeReached;
     private bool _disposeRequested;
     private bool _disposing;
     private bool _disposed;
@@ -256,6 +258,7 @@ public sealed class PortalTunnelPresentation : IDisposable
         _rotationCurrentAngle = 0f;
         _camera.DirectionDegrees = 0f;
         _waitCueVisible = false;
+        _probeFreezeReached = false;
         _visible = true;
         RebuildPose();
     }
@@ -267,6 +270,7 @@ public sealed class PortalTunnelPresentation : IDisposable
             return;
         _visible = false;
         _waitCueVisible = false;
+        _probeFreezeReached = false;
         _animationHooks.Clear();
         _sequence.ClearAnimations();
     }
@@ -275,11 +279,25 @@ public sealed class PortalTunnelPresentation : IDisposable
     {
         if (!_visible || dt < 0f)
             return;
+        if (_probeFreezeReached)
+            return;
 
         _sequence.Update(dt, frame: null);
         RebuildPose();
         _animationHooks.Drain(Vector3.Zero);
         TickRotation(dt);
+
+        if (StreamingDiagnostics.TunnelFreezeFrame is not { } freezeFrame
+            || CurrentAnimationFrame < freezeFrame)
+        {
+            return;
+        }
+
+        _probeFreezeReached = true;
+        Console.WriteLine(
+            $"[tunnel-freeze] frame={CurrentAnimationFrame} "
+            + $"target={freezeFrame} setup=0x{_setupDid:X8} "
+            + $"animation=0x{_animationDid:X8} state=held");
     }
 
     /// <summary>

src/AcDream.App/Rendering/RenderFrameDiagnosticsController.cs

@@ -128,9 +128,10 @@ internal readonly record struct ProcessResourceDiagnostics(
     int TrackedGpuTextures);
 
 /// <summary>
-/// Immutable resource facts captured only when explicit UI-probe dumping is enabled.
-/// Grouping keeps the diagnostics controller independent from every canonical renderer,
-/// VFX, mesh, texture, and process owner used to produce the values.
+/// Immutable resource facts captured only by an explicit low-frequency
+/// diagnostic such as UI-probe dumping or reveal timing. Grouping keeps the
+/// consumers independent from every canonical renderer, VFX, mesh, texture,
+/// and process owner used to produce the values.
 /// </summary>
 internal readonly record struct RenderFrameResourceDiagnosticsSnapshot(
     VfxStreamResourceDiagnostics Vfx,

src/AcDream.App/Rendering/TeleportViewPlaneController.cs

@@ -17,6 +17,7 @@ public sealed class TeleportViewPlaneController
     public const float TransitionViewPlaneDistance = 0.001f;
 
     private float _gameViewPlaneDistance = 1f;
+    private TeleportAnimState _state = TeleportAnimState.Off;
     private readonly ProjectionOverrideCamera _projectionCamera = new();
 
     public bool Enabled { get; private set; }
@@ -36,6 +37,7 @@ public sealed class TeleportViewPlaneController
 
         _gameViewPlaneDistance = distance;
         CurrentViewPlaneDistance = distance;
+        _state = TeleportAnimState.Off;
         Enabled = false;
     }
 
@@ -48,6 +50,7 @@ public sealed class TeleportViewPlaneController
     /// </summary>
     public void Update(TeleportAnimSnapshot snapshot)
     {
+        _state = snapshot.State;
         switch (snapshot.State)
         {
             case TeleportAnimState.WorldFadeOut:
@@ -80,6 +83,7 @@ public sealed class TeleportViewPlaneController
 
     public void Reset()
     {
+        _state = TeleportAnimState.Off;
         Enabled = false;
         CurrentViewPlaneDistance = _gameViewPlaneDistance;
     }
@@ -110,13 +114,35 @@ public sealed class TeleportViewPlaneController
 
         float distance = MathF.Max(CurrentViewPlaneDistance, TransitionViewPlaneDistance);
         float fov = 2f * MathF.Atan(1f / distance);
-        float near = MathF.Max(0.1f, distance * 0.25f);
+        float near = WorldTransitionNearPlane(distance);
         if (near >= far)
             near = MathF.Min(0.1f, far * 0.5f);
 
         return Matrix4x4.CreatePerspectiveFieldOfView(fov, aspect, near, far);
     }
 
+    /// <summary>
+    /// Retail's <c>set_vdst</c> keeps <c>znear</c> at 0.1 m below a view-plane
+    /// distance of 0.4. The legacy landscape path still supplied a complete
+    /// projected screen at the singular teleport endpoint. Vulkan clips the
+    /// finite resident terrain geometrically: at distance 0.001, every lower-
+    /// viewport ground ray hits the terrain before 0.1 m and the authored sky
+    /// is exposed underneath it. Scale the near plane with the transition only
+    /// while the world viewport owns the frame. This preserves the exact retail
+    /// X/Y warp, the tunnel projection, and the ordinary game projection while
+    /// giving the modern terrain path the coverage retail visibly produced.
+    /// </summary>
+    private float WorldTransitionNearPlane(float distance)
+    {
+        if (_state is TeleportAnimState.WorldFadeOut or TeleportAnimState.WorldFadeIn
+            && distance < 0.4f)
+        {
+            return MathF.Max(0.0001f, distance * 0.25f);
+        }
+
+        return MathF.Max(0.1f, distance * 0.25f);
+    }
+
     /// <summary>
     /// Decorate the active camera with the same projection returned by
     /// <see cref="Apply(Matrix4x4)"/>. Retail's <c>Render::set_vdst</c> is