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>

audit/remediation-roadmap.md

@@ -30,7 +30,7 @@ python3 .agents/skills/metin2-40250-parity-audit/scripts/port_map.py queue --lim
 
 ## 批次 2 单元（顺序以 `audit/slices/batch2-order.json` 为准，由 `port_deps.py order --write` 生成；下表仅为候选）
 
-实现位置一律是镜像文件 `extension/src/port/<Lib>/<File>.{h,cpp}`；下面列出的是需要删减旧逻辑的迁移来源。
+实现位置一律是镜像文件 `src/port/<Lib>/<File>.{h,cpp}`；下面列出的是需要删减旧逻辑的迁移来源。
 目录、CMake 目标和公共头由 2A 建立。
 
 - [ ] `UserInterface/PythonPlayerEventHandler.cpp`（OnMove/OnMoving/OnStop 已在 `net_play.gd` 对齐，需迁到镜像文件；OnWaiting DIVERGENT）— `net_play.gd`