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>

data/zh_40250/README.md

@@ -13,6 +13,6 @@
 线上字段里的 1,608 个物品名及 346 个怪物/NPC 名不含汉字，本快照原样保留。
 它们的审核译文（2026-09-28 确认）单独放在 `item_names_zh_overlay.txt`、
 `mob_names_zh_overlay.txt`，界面回退键译文在 `locale_game_zh_overlay.txt`；
-`script/build_zh_locale.py` 构建时以 overlay 覆盖快照同 VNUM / 同键的值。
+`scripts/build_zh_locale.py` 构建时以 overlay 覆盖快照同 VNUM / 同键的值。
 旧的龙驹中文表与线上表有 21 个相同 VNUM 不同名；不把旧表覆盖到服务端。
 服务端名称若再更新，需重新只读导出并核对差异后更新本快照。