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.

src/AcDream.App/Rendering/Scene/RenderProjectionJournal.cs

@@ -68,6 +68,7 @@ internal sealed class RenderProjectionJournal
         if (prior.MeshSet != current.MeshSet
             || prior.Material != current.Material
             || prior.DegradeState != current.DegradeState
+            || prior.EntityPayload != current.EntityPayload
             || prior.Source.GeometryFingerprint
                 != current.Source.GeometryFingerprint
             || prior.Source.AppearanceFingerprint