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/Inject/SinkImpl.cpp

@@ -0,0 +1,69 @@
+// SinkImpl.cpp
+// Implementation of empty functions
+
+#include "stdafx.h"
+#include "Inject.h"
+#include "SinkImpl.h"
+
+STDMETHODIMP ILayerRenderImpl::PreRender()
+{
+   return S_OK;
+}
+
+STDMETHODIMP ILayerRenderImpl::Render(ICanvas *)
+{
+   return S_OK;
+}
+
+STDMETHODIMP ILayerRenderImpl::Reformat()
+{
+	return S_OK;
+}
+
+STDMETHODIMP ILayerRenderImpl::AdjustRenderArea(ICanvas *, VARIANT_BOOL *pbDrawChildren)
+{
+   *pbDrawChildren = VARIANT_TRUE;
+	return S_OK;
+}
+
+STDMETHODIMP ILayerRenderImpl::HitTest(LPPOINT pt, VARIANT_BOOL *pbHit)
+{
+   *pbHit = VARIANT_TRUE;
+
+	return S_OK;
+}
+
+STDMETHODIMP ILayerMouseImpl::MouseEnter(struct MouseState *)
+{
+	return S_OK;
+}
+
+STDMETHODIMP ILayerMouseImpl::MouseExit(struct MouseState *)
+{
+	return S_OK;
+}
+
+STDMETHODIMP ILayerMouseImpl::MouseDown(struct MouseState *)
+{
+	return S_OK;
+}
+
+STDMETHODIMP ILayerMouseImpl::MouseUp(struct MouseState *)
+{
+	return S_OK;
+}
+
+STDMETHODIMP ILayerMouseImpl::MouseMove(struct MouseState *)
+{
+   return S_OK;
+}
+
+STDMETHODIMP ILayerMouseImpl::MouseDblClk(struct MouseState *)
+{
+   return S_OK;
+}
+
+STDMETHODIMP ILayerMouseImpl::MouseEvent(long nMsg, long wParam, long lParam)
+{
+   return S_OK;
+}