Unified logging: Replace LogSystem with EditorConsoleSink

- Created EditorConsoleSink (implements ILogSink interface)
- EditorConsoleSink stores logs in memory buffer (max 1000 entries)
- Added to Debug::Logger in Application::Initialize()
- ConsolePanel now reads from EditorConsoleSink via static GetInstance()
- Removed separate LogSystem singleton
- Removed editor/src/Core/LogEntry.h (no longer needed)

Now Editor and Engine share the same Debug::Logger, with ConsolePanel
displaying logs via EditorConsoleSink.

tests/RHI/unit/fixtures/RHITestFixture.cpp

@@ -35,7 +35,7 @@ void RHITestFixture::SetUp() {
     bool initResult = false;
     if (GetParam() == RHIType::D3D12) {
         RHIDeviceDesc desc = {};
-        desc.enableDebugLayer = true;
+        desc.enableDebugLayer = false;
         initResult = mDevice->Initialize(desc);
     } else if (GetParam() == RHIType::OpenGL) {
         auto* oglDevice = static_cast<OpenGLDevice*>(mDevice);