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>

src/port/common/shim/sdk/Python-2.7/parsetok.h

@@ -0,0 +1,13 @@
+#pragma once
+// Shim for 40250's <Python-2.7/parsetok.h>: the client includes the CPython headers under a
+// Python-2.7/ prefix (its extern/include layout). The vendored interpreter
+// (third_party/cpython-2.7.18, target mtpython) installs them flat, so each header
+// here forwards to the real one. <Python-2.7/python.h> comes first in 40250's StdAfx, exactly
+// as CPython requires of <Python.h>; this shim includes it first so the header also stands
+// alone under the port header gate.
+#include <Python.h>
+// parsetok.h names `node` and `grammar` without including their headers; 40250's StdAfx includes
+// node.h and grammar.h before it, in this order.
+#include <node.h>
+#include <grammar.h>
+#include <parsetok.h>