Fix RenderDoc OpenGL capture - pass HGLRC instead of HDC

Critical fix: For OpenGL, RenderDoc requires HGLRC (OpenGL context) as
the device pointer, not HDC. Previously OpenGL test incorrectly passed
HDC which caused capture to silently fail (NumCaptures=0).

Changes:
- OpenGLDevice: Add wglCreateContextAttribsARB support for debug context
- OpenGLDevice: Create OpenGL 4.6 core profile with debug flag
- RenderDocCapture: Pass correct window to SetActiveWindow/StartFrameCapture
- OpenGL test: Pass HGLRC via SetDevice(), use BeginCapture/EndCapture

Fix root cause identified via RenderDoc docs analysis:
  'For OpenGL it must be the HGLRC, GLXContext, or EGLContext'

engine/src/Debug/RenderDocCapture.cpp

@@ -122,14 +122,19 @@ void RenderDocCapture::BeginCapture(const char* title) {
     if (title) {
         m_api->SetCaptureTitle(title);
     }
-    m_api->StartFrameCapture(m_device, nullptr);
+    
+    SetForegroundWindow((HWND)m_window);
+    SetFocus((HWND)m_window);
+    
+    m_api->SetActiveWindow(m_device, m_window);
+    m_api->StartFrameCapture(m_device, m_window);
 }
 
 void RenderDocCapture::EndCapture() {
     if (!m_isLoaded || !m_api) {
         return;
     }
-    m_api->EndFrameCapture(m_device, nullptr);
+    m_api->EndFrameCapture(m_device, m_window);
 }
 
 void RenderDocCapture::TriggerCapture() {