Add hierarchical scene graph for editor with TreeView UI, runtime
HierarchyUtility for parent/child linked-list management, and
incremental sync between editor world and scene graph nodes.
- SceneGraphNode/SceneNode/EntityNode with World, Scene, Entity refs
- SceneGraphBuilder — construct tree from ECS World queries
- HierarchyUtility — SetParent, RemoveParent, IsAncestor, cascade destroy
- EditorWorldService + SceneGraphSyncService — editor world lifecycle & incremental sync
- Hierarchy.xaml — TreeView with DataTemplate + SceneGraphTemplateSelector
- 25 unit tests covering hierarchy ops and scene graph building
Misaki
2ea3c509b0