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.

editor/src/Application.cpp

@@ -1,6 +1,7 @@
 #include "Application.h"
 #include "Layers/EditorLayer.h"
 #include "Core/EditorContextImpl.h"
+#include "Core/EditorConsoleSink.h"
 #include <XCEngine/Debug/Logger.h>
 #include <XCEngine/Debug/FileLogSink.h>
 #include <XCEngine/Debug/ConsoleLogSink.h>
@@ -66,6 +67,7 @@ bool Application::Initialize(HWND hwnd) {
     
     // Initialize logging first
     Debug::Logger::Get().AddSink(std::make_unique<Debug::ConsoleLogSink>());
+    Debug::Logger::Get().AddSink(std::make_unique<Debug::EditorConsoleSink>());
     
     // Get exe directory for log file path
     wchar_t exePath[MAX_PATH];