Initial commit: Complete open-source Decal rebuild

All 5 phases of the open-source Decal rebuild:

Phase 1: 14 decompiled .NET projects (Interop.*, Adapter, FileService, DecalUtil)
Phase 2: 10 native DLLs rewritten as C# COM servers with matching GUIDs
  - DecalDat, DHS, SpellFilter, DecalInput, DecalNet, DecalFilters
  - Decal.Core, DecalControls, DecalRender, D3DService
Phase 3: C++ shims for Inject.DLL (D3D9 hooking) and LauncherHook.DLL
Phase 4: DenAgent WinForms tray application
Phase 5: WiX installer and build script

25 C# projects building with 0 errors.
Native C++ projects require VS 2022 + Windows SDK (x86).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Native/DecalControls/ChoicePopup.h

@@ -0,0 +1,87 @@
+// ChoicePopup.h : Declaration of the cChoicePopup
+
+#ifndef __CHOICEPOPUP_H_
+#define __CHOICEPOPUP_H_
+
+#include "resource.h"       // main symbols
+
+#include "SinkImpl.h"
+
+class cChoice;
+
+/////////////////////////////////////////////////////////////////////////////
+// cChoicePopup
+class ATL_NO_VTABLE cChoicePopup : 
+	public CComObjectRootEx<CComMultiThreadModel>,
+   public ILayerImpl< cChoicePopup >,
+   public ILayerRenderImpl,
+   public ILayerMouseImpl,
+   public cNoEventsImpl,
+	public IChoicePopup
+{
+public:
+	cChoicePopup()
+      : m_pChoice( NULL ),
+      m_bMouseDown( false )
+	{
+	}
+
+   cChoice *m_pChoice;
+   CComPtr< IImageCache > m_pActive;
+   bool m_bMouseDown;
+
+   void onCreate();
+   void onDestroy();
+
+BEGIN_COM_MAP(cChoicePopup)
+   COM_INTERFACE_ENTRY(ILayerRender)
+   COM_INTERFACE_ENTRY(ILayerMouse)
+   COM_INTERFACE_ENTRY(ILayer)
+	COM_INTERFACE_ENTRY(IChoicePopup)
+END_COM_MAP()
+
+   void hotSelect( MouseState *pMS );
+
+public:
+   // IChoicePopup Methods
+
+   // ILayerRender Methods
+   STDMETHOD(Render)(ICanvas *pCanvas);
+
+   // ILayerMouse Methods
+   STDMETHOD(MouseDown)(MouseState *pMS)
+   {
+      m_bMouseDown = true;
+      hotSelect( pMS );
+
+      return S_OK;
+   }
+
+   STDMETHOD(MouseEnter)(MouseState *pMS)
+   {
+      if( m_bMouseDown )
+         hotSelect( pMS );
+
+      return S_OK;
+   }
+
+   STDMETHOD(MouseExit)(MouseState *pMS)
+   {
+      if( m_bMouseDown )
+         hotSelect( pMS );
+
+      return S_OK;
+   }
+
+   STDMETHOD(MouseMove)(MouseState *pMS)
+   {
+      if( m_bMouseDown )
+         hotSelect( pMS );
+
+      return S_OK;
+   }
+
+   STDMETHOD(MouseUp)(MouseState *pMS);
+};
+
+#endif //__CHOICEPOPUP_H_