add transient nav coverage hints

Introduce nav-only corridor hints and feed them into clustered coverage scheduling so runtime NavMesh can prewarm ahead of active movement paths.

Assets/Scripts/VoxelWorld/VoxelWorldNavMeshLifetimeScope.cs

@@ -32,6 +32,7 @@ namespace VoxelWorldScene
             builder.RegisterInstance(config);
             builder.RegisterInstance(worldGenerator).As<IChunkNavSourceReader>().AsSelf();
             builder.Register<SceneWorldInterestReader>(Lifetime.Singleton).As<IWorldInterestReader>();
+            builder.RegisterEntryPoint<NavCoverageHintService>().AsSelf();
             builder.RegisterEntryPoint<VoxelWorldNavMeshService>().AsSelf();
             builder.RegisterBuildCallback(ResolvePublishers);
         }