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/CMakeLists.txt

@@ -0,0 +1,11 @@
+# port_platform — platform-layer implementations of the mirrored 40250 headers
+# (extension/src/platform/<Lib>/<File>.cpp for extension/src/port/<Lib>/<File>.h). Starts as the empty
+# skeleton generated by platform_stub.py; see docs/PORT-PLAN.md batch 2A. Added from port/CMakeLists.txt
+# so it shares the per-library definitions.
+
+file(GLOB_RECURSE MT_PLATFORM_SOURCES CONFIGURE_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/*.cpp)
+add_library(port_platform STATIC ${MT_PLATFORM_SOURCES})
+target_link_libraries(port_platform PUBLIC port_logic)
+foreach(src IN LISTS MT_PLATFORM_SOURCES)
+    mt_port_apply_defines(${src})
+endforeach()