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/D3D12/D3D12CommandList.cpp

@@ -276,9 +276,24 @@ void D3D12CommandList::AliasBarrierInternal(ID3D12Resource* beforeResource, ID3D
 
 void D3D12CommandList::BeginRenderPass(RHIRenderPass* renderPass, RHIFramebuffer* framebuffer,
                                      const Rect& renderArea, uint32_t clearValueCount, const ClearValue* clearValues) {
-    (void)renderArea;
     if (!framebuffer || !renderPass) return;
 
+    D3D12_VIEWPORT d3dViewport = {};
+    d3dViewport.TopLeftX = static_cast<float>(renderArea.left);
+    d3dViewport.TopLeftY = static_cast<float>(renderArea.top);
+    d3dViewport.Width = static_cast<float>(renderArea.right - renderArea.left);
+    d3dViewport.Height = static_cast<float>(renderArea.bottom - renderArea.top);
+    d3dViewport.MinDepth = 0.0f;
+    d3dViewport.MaxDepth = 1.0f;
+    m_commandList->RSSetViewports(1, &d3dViewport);
+
+    D3D12_RECT d3dScissor = {};
+    d3dScissor.left = renderArea.left;
+    d3dScissor.top = renderArea.top;
+    d3dScissor.right = renderArea.right;
+    d3dScissor.bottom = renderArea.bottom;
+    m_commandList->RSSetScissorRects(1, &d3dScissor);
+
     D3D12Framebuffer* d3d12Framebuffer = static_cast<D3D12Framebuffer*>(framebuffer);
 
     uint32_t rtCount = d3d12Framebuffer->GetRenderTargetCount();

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();