feat(rendering): pack scene dispatcher inputs

Capture immutable presentation payloads in the render scene, flatten unique entity and mesh-part records into the borrowed frame arena, and compare every routed dispatcher input tuple without changing the production draw source.

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

@@ -2,6 +2,7 @@ using System.Numerics;
 using AcDream.App.Rendering;
 using AcDream.App.Rendering.Scene;
 using AcDream.Core.Selection;
+using AcDream.Core.World;
 
 namespace AcDream.App.Tests.Rendering;
 
@@ -26,6 +27,7 @@ public sealed class RenderFrameProductTests
             dynamic.Id,
             0,
             Matrix4x4.CreateTranslation(1, 2, 3)));
+        writer.AddEntityCandidate(in dynamic, animated: true);
         writer.AddClassification(new RenderFrameClassificationRecord(
             outdoor.Id,
             0,
@@ -85,8 +87,16 @@ public sealed class RenderFrameProductTests
                 1),
             view.RouteRanges[0]);
         Assert.Equal(
-            new RenderFrameDiagnosticCounts(1, 2, 1, 1, 1, 1, 1, 1, 1),
+            new RenderFrameDiagnosticCounts(
+                1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1),
             view.DiagnosticCounts);
+        RenderFrameEntityCandidate packed = Assert.Single(
+            view.EntityCandidates.ToArray());
+        Assert.Equal(dynamic.Id, packed.Projection.Id);
+        Assert.True(packed.Animated);
+        RenderFrameMeshPart part = Assert.Single(view.MeshParts.ToArray());
+        Assert.Equal(dynamic.Id, part.ProjectionId);
+        Assert.Equal(0, part.PartIndex);
         Assert.Equal(digest, view.SourceDigest);
 
         exchange.Release(in view);
@@ -231,6 +241,7 @@ public sealed class RenderFrameProductTests
             record.Id,
             0,
             Matrix4x4.Identity));
+        writer.AddEntityCandidate(in record, animated: false);
         writer.AddClassification(new RenderFrameClassificationRecord(
             record.Id,
             0,
@@ -277,6 +288,10 @@ public sealed class RenderFrameProductTests
             Transform = new RenderTransform(Matrix4x4.Identity),
             PreviousTransform = new PreviousRenderTransform(Matrix4x4.Identity),
             Flags = RenderProjectionFlags.Draw,
+            EntityPayload = new RenderEntityPayload(
+                [new MeshRef((uint)value, Matrix4x4.Identity)],
+                PaletteOverride: null,
+                IsBuildingShell: false),
         };
 
     private static RetailSelectionMesh SelectionMesh() =>