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/src/RHI/OpenGL/OpenGLCommandList.cpp

@@ -489,6 +489,8 @@ void OpenGLCommandList::BeginRenderPass(RHIRenderPass* renderPass, RHIFramebuffe
     OpenGLFramebuffer* glFramebuffer = static_cast<OpenGLFramebuffer*>(framebuffer);
     glFramebuffer->Bind();
     
+    if (!renderPass) return;
+    
     OpenGLRenderPass* glRenderPass = static_cast<OpenGLRenderPass*>(renderPass);
     if (glRenderPass) {
         const AttachmentDesc* colorAttachments = glRenderPass->GetColorAttachments();