refactor(editor): Complete architecture refactoring

- SceneManager: remove singleton, use dependency injection via EditorContext
- SelectionManager: already interface-based via ISelectionManager
- Panel: now receives IEditorContext for accessing managers
- HierarchyPanel: migrated to use IEditorContext instead of singletons
- Add ISceneManager interface and SceneManagerImpl
- EditorContextImpl: holds all editor subsystems

Architecture now follows dependency injection pattern:
Application -> EditorContext -> SceneManager/SelectionManager
EditorLayer -> Panels (receive context via SetContext)

All Manager singletons removed: EditorSceneManager::Get(), SelectionManager::Get()

engine/include/XCEngine/RHI/RHIDescriptorSet.h

@@ -29,6 +29,7 @@ public:
     virtual void Shutdown() = 0;
     virtual void Update(uint32_t offset, RHIResourceView* view) = 0;
     virtual void UpdateSampler(uint32_t offset, RHISampler* sampler) = 0;
+
     virtual void* GetNativeHandle() = 0;
 
     virtual uint32_t GetBindingCount() const = 0;