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>

third_party/cpython-2.7.18/Python/pystrcmp.c

@@ -0,0 +1,26 @@
+/* Cross platform case insensitive string compare functions
+ */
+
+#include "Python.h"
+
+int
+PyOS_mystrnicmp(const char *s1, const char *s2, Py_ssize_t size)
+{
+    if (size == 0)
+        return 0;
+    while ((--size > 0) &&
+           (tolower((unsigned)*s1) == tolower((unsigned)*s2))) {
+        if (!*s1++ || !*s2++)
+            break;
+    }
+    return tolower((unsigned)*s1) - tolower((unsigned)*s2);
+}
+
+int
+PyOS_mystricmp(const char *s1, const char *s2)
+{
+    while (*s1 && (tolower((unsigned)*s1++) == tolower((unsigned)*s2++))) {
+        ;
+    }
+    return (tolower((unsigned)*s1) - tolower((unsigned)*s2));
+}