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/platform/MilesLib/SoundData.cpp

@@ -0,0 +1,116 @@
+// Platform skeleton for MilesLib/SoundData.h (40250 MilesLib/SoundData.cpp), generated by platform_stub.py.
+// Every MT_PLATFORM_STUB() body is unimplemented: replace it with the platform implementation.
+#include "MilesLib/Stdafx.h"
+#include "MilesLib/SoundData.h"
+
+#include "../PlatformStub.h"
+
+auto CSoundData::SetPackMode() -> void
+{
+	MT_PLATFORM_STUB();
+}
+
+CSoundData::CSoundData()
+{
+	MT_PLATFORM_STUB();
+}
+
+CSoundData::~CSoundData()
+{
+	MT_PLATFORM_STUB();
+}
+
+auto CSoundData::Assign(const char *) -> void
+{
+	MT_PLATFORM_STUB();
+}
+
+auto CSoundData::Get() -> LPVOID
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<LPVOID>();
+}
+
+auto CSoundData::GetSize() -> ULONG
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<ULONG>();
+}
+
+auto CSoundData::Release() -> void
+{
+	MT_PLATFORM_STUB();
+}
+
+auto CSoundData::GetAccessTime() -> DWORD
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<DWORD>();
+}
+
+auto CSoundData::GetFileName() -> const char *
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<const char *>();
+}
+
+auto CSoundData::SetPlayTime(DWORD) -> void
+{
+	MT_PLATFORM_STUB();
+}
+
+auto CSoundData::GetPlayTime() -> DWORD
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<DWORD>();
+}
+
+auto CSoundData::ReadFromDisk() -> bool
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<bool>();
+}
+
+auto CSoundData::Destroy() -> void
+{
+	MT_PLATFORM_STUB();
+}
+
+auto CSoundData::open_callback(const char *, U32 *) -> U32
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<U32>();
+}
+
+auto CSoundData::close_callback(U32) -> void
+{
+	MT_PLATFORM_STUB();
+}
+
+auto CSoundData::seek_callback(U32, S32, U32) -> S32
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<S32>();
+}
+
+auto CSoundData::read_callback(U32, void *, U32) -> U32
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<U32>();
+}
+
+auto CSoundData::isSlotIndex(DWORD) -> bool
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<bool>();
+}
+
+auto CSoundData::GetEmptySlotIndex() -> int
+{
+	MT_PLATFORM_STUB();
+	return mt_platform_stub_return<int>();
+}
+
+decltype(CSoundData::ms_isSoundFile) CSoundData::ms_isSoundFile{};
+
+decltype(CSoundData::ms_SoundFile) CSoundData::ms_SoundFile{};