port 2D step 5a: EterPack/EterPackManager + EterBase file units against the real 40250 packs

- Mirror copies: EterPack (EterPack, EterPackManager, EterPackCursor, CSHybridCrypt policy, Inline.h)
  and EterBase logic units tea/lzo/Timer/Stl/Random, with PORT-tagged width fixes (LONG index
  fields, static_assert(sizeof(TEterPackIndex) == 192), tea_word = Win32 unsigned long).
- TEA pack keys are extracted from the reference EterPack.cpp at configure time into
  build/.../EterPackKeys.generated.h; nothing key-bearing is tracked.
- Platform EterBase: FileBase (stdio, case-insensitive fallback), MappedFile (mmap /
  MapViewOfFile), CRC32, Debug, Utils StringPath/StringLowers.
- Win32Crt: CreateDirectory/DeleteFile/_access/MAKEFOURCC; Win32MinMax.h min/max (force-included
  on MinGW, whose windows.h omits them in C++).
- tests/port_eterpack_test: registers pack/Index like PackInitialize and checks 119
  registrations / 103 packs + root / 54891 entries / 52609 paths / 2282 overrides with
  first-registered-wins, and that exactly the 4 short-layout SECURITY files fail to load.
- 2R count corrected (136 -> 119 registrations, 103 distinct packs + root).

Not runtime-reachable yet (asset_io pack backend is step 5b), so port-map statuses stay TODO.
port_gate: macos/android/ios/windows PASS.

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

extension/src/port/common/Win32Crt.cpp

@@ -8,6 +8,9 @@
 #include <new>
 #include <vector>
 
+#include <sys/stat.h>
+#include <unistd.h>
+
 static_assert(sizeof(std::recursive_mutex) <= sizeof(CRITICAL_SECTION::storage), "CRITICAL_SECTION storage");
 static_assert(alignof(std::recursive_mutex) <= 16, "CRITICAL_SECTION alignment");
 
@@ -21,6 +24,26 @@ void DeleteCriticalSection(LPCRITICAL_SECTION cs) { cs_mutex(cs).~recursive_mute
 void EnterCriticalSection(LPCRITICAL_SECTION cs) { cs_mutex(cs).lock(); }
 void LeaveCriticalSection(LPCRITICAL_SECTION cs) { cs_mutex(cs).unlock(); }
 
+BOOL CreateDirectory(LPCSTR path, void*)
+{
+	return mkdir(path, 0777) == 0 ? TRUE : FALSE;
+}
+
+BOOL DeleteFile(LPCSTR path)
+{
+	return unlink(path) == 0 ? TRUE : FALSE;
+}
+
+int _access(const char* path, int mode)
+{
+	int m = F_OK;
+	if (mode & 2)
+		m |= W_OK;
+	if (mode & 4)
+		m |= R_OK;
+	return access(path, m);
+}
+
 char* _strlwr(char* s)
 {
 	for (char* p = s; *p; ++p)

extension/src/port/common/Win32Crt.h

@@ -12,6 +12,14 @@
 #if !defined(_WIN32)
 #include <strings.h>
 
+#include "Win32MinMax.h"
+
+// mmsystem.h
+#ifndef MAKEFOURCC
+#define MAKEFOURCC(ch0, ch1, ch2, ch3) \
+	((DWORD)(BYTE)(ch0) | ((DWORD)(BYTE)(ch1) << 8) | ((DWORD)(BYTE)(ch2) << 16) | ((DWORD)(BYTE)(ch3) << 24))
+#endif
+
 #define ZeroMemory(dst, len) std::memset((dst), 0, (len))
 #define FillMemory(dst, len, fill) std::memset((dst), (fill), (len))
 #define CopyMemory(dst, src, len) std::memcpy((dst), (src), (len))
@@ -41,6 +49,12 @@ int _snprintf(char* buf, size_t count, const char* fmt, ...)
 #endif
 	;
 
+// kernel32 file-system calls (ANSI). CreateDirectory ignores the security attributes; _access takes
+// the MSVC modes 0 (exists), 2 (write), 4 (read), 6 (read/write).
+BOOL CreateDirectory(LPCSTR path, void* security_attributes);
+BOOL DeleteFile(LPCSTR path);
+int _access(const char* path, int mode);
+
 // winmm `timeGetTime`: milliseconds since system start, wrapping at 2^32.
 DWORD timeGetTime();
 DWORD GetTickCount();

extension/src/port/common/Win32MinMax.h

@@ -0,0 +1,13 @@
+#pragma once
+// windef.h `min`/`max` macros (40250 builds without NOMINMAX), as functions so <algorithm> and
+// numeric_limits<T>::max() keep working: same usual-arithmetic-conversion result as the macro, and a
+// same-typed call under `using namespace std` still resolves to the more specialized std::min/max.
+// Included by Win32Crt.h off Windows, and force-included on MinGW, whose <windows.h> leaves them out in C++.
+#include <type_traits>
+
+#if !defined(min) && !defined(max)
+template <class A, class B>
+constexpr std::common_type_t<A, B> min(A a, B b) { return (a < b) ? a : b; }
+template <class A, class B>
+constexpr std::common_type_t<A, B> max(A a, B b) { return (a > b) ? a : b; }
+#endif

extension/src/port/common/shim/sdk/cryptopp/cryptoppLibLink.h

@@ -0,0 +1,3 @@
+#pragma once
+// Shim for 40250's <cryptopp/cryptoppLibLink.h>, which only holds MSVC `#pragma comment(lib, ...)` auto-link
+// lines; the vendored Crypto++ (mt3p::cryptopp) is linked by CMake.

extension/src/port/common/shim/sdk/lzo/lzoLibLink.h

@@ -0,0 +1,3 @@
+#pragma once
+// Shim for 40250's <lzo/lzoLibLink.h>, which only holds MSVC `#pragma comment(lib, ...)` auto-link lines;
+// the vendored minilzo (mt3p::minilzo) is linked by CMake.

extension/src/port/common/shim/win32/io.h

@@ -0,0 +1,3 @@
+#pragma once
+// Shim for <io.h> on non-Windows targets; what 40250 logic uses from it (_access) is in <windows.h>.
+#include "windows.h"