layout: restructure into src/ tests/ android/ scripts/ tools/

- extension/src/{port,platform,codepage} -> src/; native_render -> src/host
  (+ dxt, shaders/); libgr2 -> src/gr2; extension/third_party -> third_party
- extension/tests -> tests/port, libgr2/tests -> tests/gr2
- android-native -> android (build.sh, push-client.sh moved in)
- script -> scripts; tools/40250 -> tools/server; oracle -> tools/granny-oracle;
  perf tools -> tools/perf
- all build trees under build/ (native, release, android, port-gate)
- xrender:: CMake aliases -> mt::; port-map ledger impl paths rewritten

No code changes. ctest 15/15, port_gate macos+android PASS, port_map check 0 errors.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tools/granny-oracle/CMakeLists.txt

@@ -0,0 +1,46 @@
+# oracle —— 独立 Windows 工程（不在主 CMake 树内）。见 ../docs/steps/00-oracle.md、RUNBOOK.md
+#
+#   cmake -S oracle -B tools/granny-oracle/build -DGRANNY_SDK=<泄露 SDK 根>
+#   cmake --build tools/granny-oracle/build --config Release
+#
+# GRANNY_SDK 默认指向本仓库同级的 MobileSource 里的 Granny-3D-SDK-main。
+# 链 granny2_x64.lib（import lib）；运行时需要对应的 granny2_x64.dll 在 PATH / exe 目录。
+# ⚠ 这个 DLL 是 SDK 2.9.12。资产由 2.4.0.7 导出（M0 T2 实测）。容器 + 组合公式在 2.4–2.11
+#   稳定，但 B 样条边界 / 少数曲线细节可能有差异 —— 先跑 selfcheck（T7）确认坐标约定，
+#   再决定是否要换成 2.4.x 的 runtime DLL（见 GRANNY-VERSION.md）。
+
+cmake_minimum_required(VERSION 3.20)
+project(xrender_oracle C)
+
+set(CMAKE_C_STANDARD 11)
+
+set(GRANNY_SDK "${CMAKE_SOURCE_DIR}/../../../MobileSource/Cross Platform/Granny-3D-SDK-main"
+    CACHE PATH "泄露 Granny SDK 根（含 include/ 和 lib/win64/）")
+
+if(NOT EXISTS "${GRANNY_SDK}/include/granny.h")
+    message(FATAL_ERROR "找不到 ${GRANNY_SDK}/include/granny.h —— 传 -DGRANNY_SDK=<SDK 根>")
+endif()
+
+add_executable(oracle oracle.c)
+target_include_directories(oracle PRIVATE "${GRANNY_SDK}/include")
+
+if(WIN32)
+    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+        target_link_libraries(oracle PRIVATE "${GRANNY_SDK}/lib/win64/granny2_x64.lib")
+        set(_dll "${GRANNY_SDK}/lib/win64/granny2_x64.dll")
+    else()
+        target_link_libraries(oracle PRIVATE "${GRANNY_SDK}/lib/win32/granny2.lib")
+        set(_dll "${GRANNY_SDK}/lib/win32/granny2.dll")
+    endif()
+    # 把 DLL 拷到 exe 旁边，方便直接跑 / Wine
+    add_custom_command(TARGET oracle POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different "${_dll}" "$<TARGET_FILE_DIR:oracle>")
+else()
+    message(WARNING
+        "非 Windows：SDK 只提供 win32/win64/wii/ps3/xenon 的 granny2 预编译库。\n"
+        "  选项 A：在 Windows 机器 / VM 上 build+run。\n"
+        "  选项 B：Wine（oracle 只做文件 IO + 数学 + 写二进制，不碰 GPU，Wine 够用）——\n"
+        "          用 MinGW 交叉编译或直接在 Wine 里跑 MSVC，链 granny2_x64.lib。\n"
+        "  选项 C（stretch）：从 SDK source/ 移植 winxx/ 平台层出一个 POSIX libgranny。\n"
+        "  见 RUNBOOK.md。")
+endif()