port 2A step 4: platform skeleton + rest of the 2V3 header closure

- Mirror the remaining non-Python 2V3 closure headers (98 more, 173 total): EffectLib,
  EterGrnLib, SpeedTreeLib, SphereLib, PRTerrainLib, EterImageLib, EterBase/Poly, cipher/tea,
  EterLib Grp*/IME/Input/MSWindow/StateManager, GameLib actor/map/race headers, EterPack.
- SDK shims: granny.h, SpeedTreeRT.h, imm.h, Dimm.h (the SDK MIDL header, not mirrored),
  dinput/d3dx8 additions; D3D8 render-state enums, FVF macros and the COM resource hierarchy;
  more Win32 GDI/handle types with layout static_asserts.
- PORT edits for MSVC-permissive code (typename, friend visibility, <algorithm>, pointer→uintptr_t)
  and PRTerrainLib/StdAfx.h dropping the ScriptLib/Python include.
- port_logic links the vendored cryptopp/minilzo.
- extension/src/platform: port_platform target with 103 generated stub files (1917 function
  stubs, 146 static members) from the new platform_stub.py (clang -ast-dump-filter);
  MT_PLATFORM_STUB() marks every unimplemented body. libmtgodot links port_platform and
  port_gate.sh builds it.

Gate: macOS, Android, iOS, Windows (mingw) PASS; Linux BLOCKED (no toolchain).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

extension/src/port/EterLib/GrpShadowTexture.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include "GrpTexture.h"
+
+class CGraphicShadowTexture : public CGraphicTexture
+{
+	public:
+		CGraphicShadowTexture();
+		virtual ~CGraphicShadowTexture();
+		
+		void Destroy();
+		
+		bool Create(int width, int height);
+
+		void Begin();
+		void End();
+		void Set(int stage = 0) const;
+
+		const D3DXMATRIX& GetLightVPMatrixReference() const;
+		LPDIRECT3DTEXTURE8 GetD3DTexture() const;
+
+	protected:
+		void Initialize();
+		
+	protected:
+		D3DXMATRIX			m_d3dLightVPMatrix;
+		D3DVIEWPORT8		m_d3dOldViewport;
+		
+		LPDIRECT3DTEXTURE8	m_lpd3dShadowTexture;
+		LPDIRECT3DSURFACE8	m_lpd3dShadowSurface;
+		LPDIRECT3DSURFACE8	m_lpd3dDepthSurface;
+
+		LPDIRECT3DSURFACE8	m_lpd3dOldBackBufferSurface;
+		LPDIRECT3DSURFACE8	m_lpd3dOldDepthBufferSurface;
+};