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/DecalNet/ProtocolStack.h

@@ -0,0 +1,106 @@
+// ProtocolStack.h
+// Declaration of class cProtocolStack
+
+#ifndef __PROTOCOLSTACK_H
+#define __PROTOCOLSTACK_H
+
+#include "ACMessage.h"
+
+#define DEFAULT_HEADER_SIZE 16
+#define FRAGMENT_SIZE 448
+
+#pragma pack( push, 1 )
+// The packet header
+struct cPacketHeader
+{
+	DWORD	m_dwSequence;
+	DWORD	m_dwFlags;
+	DWORD	m_dwCRC;
+
+	WORD	m_wUnk1;
+	WORD	m_wUnk2;
+	WORD	m_wTotalSize;
+	WORD	m_wUnk3;
+};
+#pragma pack( pop )
+
+class cMessageStack
+{
+public:
+#pragma pack( push, 1 )
+   struct cMessageHeader
+   {
+      DWORD m_dwSequence;
+      DWORD m_dwObjectID;
+      WORD m_wFragmentCount;
+      WORD m_wFragmentLength;
+      WORD m_wFragmentIndex,
+         m_wUnknown1;
+   };
+#pragma pack( pop )
+
+   class cProtocolMessage : public ACMessage
+   {
+   protected:
+      mutable BYTE *m_pbData;
+      mutable bool *m_pbReceived;
+      mutable bool m_bOwn;
+
+   public:
+      cProtocolMessage( BYTE *pbData );
+      cProtocolMessage( const cProtocolMessage &msg );
+      ~cProtocolMessage();
+
+      cMessageHeader *getMessageHeader() const
+      {
+         return reinterpret_cast< cMessageHeader * >( m_pbData );
+      }
+
+      cProtocolMessage &operator= ( const cProtocolMessage &msg );
+
+	  // ACMessage interface implementation for protocol stack
+	  virtual BYTE *getData ()
+	  {
+         return m_pbData + sizeof( cMessageHeader );
+	  }
+
+	  virtual DWORD getSize ()
+	  {
+         return getMessageHeader()->m_wFragmentLength - sizeof( cMessageHeader );
+	  }
+
+	  virtual DWORD getType ()
+	  {
+         return *reinterpret_cast< DWORD * >( m_pbData + sizeof( cMessageHeader ) );
+	  }
+
+      bool isComplete() const;
+
+      bool fragmentMatch( BYTE *pFragmentStart );
+      void insertFragment( BYTE *pFragmentStart );
+
+      static DWORD calcMessageLength( BYTE *pbHeader );
+   };
+
+private:
+   typedef std::list< cProtocolMessage > cMessageList;
+
+   ACMessageSink *m_pCallback;
+   cMessageList m_messages;
+
+public:
+   cMessageStack();
+   ~cMessageStack();
+
+   void start( ACMessageSink * );
+   void stop();
+
+   void processPacket( DWORD dwLength, BYTE *pbPayload );
+   void processPacketOut( DWORD dwLength, const BYTE *pbPayload );
+
+private:
+   void splitPacket( DWORD dwLength, BYTE *pbPayload );
+   void splitPacketOut( DWORD dwLength, const BYTE *pbPayload );
+};
+
+#endif