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/DenAgent/ReadMe.txt

@@ -0,0 +1,88 @@
+========================================================================
+       MICROSOFT FOUNDATION CLASS LIBRARY : DenAgent
+========================================================================
+
+
+AppWizard has created this DenAgent application for you.  This application
+not only demonstrates the basics of using the Microsoft Foundation classes
+but is also a starting point for writing your application.
+
+This file contains a summary of what you will find in each of the files that
+make up your DenAgent application.
+
+DenAgent.dsp
+    This file (the project file) contains information at the project level and
+    is used to build a single project or subproject. Other users can share the
+    project (.dsp) file, but they should export the makefiles locally.
+
+DenAgent.h
+    This is the main header file for the application.  It includes other
+    project specific headers (including Resource.h) and declares the
+    CDenAgentApp application class.
+
+DenAgent.cpp
+    This is the main application source file that contains the application
+    class CDenAgentApp.
+
+DenAgent.rc
+    This is a listing of all of the Microsoft Windows resources that the
+    program uses.  It includes the icons, bitmaps, and cursors that are stored
+    in the RES subdirectory.  This file can be directly edited in Microsoft
+	Visual C++.
+
+DenAgent.clw
+    This file contains information used by ClassWizard to edit existing
+    classes or add new classes.  ClassWizard also uses this file to store
+    information needed to create and edit message maps and dialog data
+    maps and to create prototype member functions.
+
+res\DenAgent.ico
+    This is an icon file, which is used as the application's icon.  This
+    icon is included by the main resource file DenAgent.rc.
+
+res\DenAgent.rc2
+    This file contains resources that are not edited by Microsoft 
+	Visual C++.  You should place all resources not editable by
+	the resource editor in this file.
+
+
+
+
+/////////////////////////////////////////////////////////////////////////////
+
+AppWizard creates one dialog class:
+
+DenAgentDlg.h, DenAgentDlg.cpp - the dialog
+    These files contain your CDenAgentDlg class.  This class defines
+    the behavior of your application's main dialog.  The dialog's
+    template is in DenAgent.rc, which can be edited in Microsoft
+	Visual C++.
+
+
+/////////////////////////////////////////////////////////////////////////////
+Other standard files:
+
+StdAfx.h, StdAfx.cpp
+    These files are used to build a precompiled header (PCH) file
+    named DenAgent.pch and a precompiled types file named StdAfx.obj.
+
+Resource.h
+    This is the standard header file, which defines new resource IDs.
+    Microsoft Visual C++ reads and updates this file.
+
+/////////////////////////////////////////////////////////////////////////////
+Other notes:
+
+AppWizard uses "TODO:" to indicate parts of the source code you
+should add to or customize.
+
+If your application uses MFC in a shared DLL, and your application is 
+in a language other than the operating system's current language, you
+will need to copy the corresponding localized resources MFC42XXX.DLL
+from the Microsoft Visual C++ CD-ROM onto the system or system32 directory,
+and rename it to be MFCLOC.DLL.  ("XXX" stands for the language abbreviation.
+For example, MFC42DEU.DLL contains resources translated to German.)  If you
+don't do this, some of the UI elements of your application will remain in the
+language of the operating system.
+
+/////////////////////////////////////////////////////////////////////////////