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/cryptopp/gf2_32.h

@@ -0,0 +1,73 @@
+// gf2_32.h - originally written and placed in the public domain by Wei Dai
+
+/// \file gf2_32.h
+/// \brief Classes and functions for schemes over GF(2^32)
+
+#ifndef CRYPTOPP_GF2_32_H
+#define CRYPTOPP_GF2_32_H
+
+#include "cryptlib.h"
+#include "secblock.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+/// \brief GF(2^32) with polynomial basis
+class GF2_32
+{
+public:
+	typedef word32 Element;
+	typedef int RandomizationParameter;
+
+	GF2_32(word32 modulus=0x0000008D) : m_modulus(modulus) {}
+
+	Element RandomElement(RandomNumberGenerator &rng, int ignored = 0) const
+		{CRYPTOPP_UNUSED(ignored); return rng.GenerateWord32();}
+
+	bool Equal(Element a, Element b) const
+		{return a==b;}
+
+	Element Identity() const
+		{return 0;}
+
+	Element Add(Element a, Element b) const
+		{return a^b;}
+
+	Element& Accumulate(Element &a, Element b) const
+		{return a^=b;}
+
+	Element Inverse(Element a) const
+		{return a;}
+
+	Element Subtract(Element a, Element b) const
+		{return a^b;}
+
+	Element& Reduce(Element &a, Element b) const
+		{return a^=b;}
+
+	Element Double(Element a) const
+		{CRYPTOPP_UNUSED(a); return 0;}
+
+	Element MultiplicativeIdentity() const
+		{return 1;}
+
+	Element Multiply(Element a, Element b) const;
+
+	Element Square(Element a) const
+		{return Multiply(a, a);}
+
+	bool IsUnit(Element a) const
+		{return a != 0;}
+
+	Element MultiplicativeInverse(Element a) const;
+
+	Element Divide(Element a, Element b) const
+		{return Multiply(a, MultiplicativeInverse(b));}
+
+private:
+	word32 m_modulus;
+};
+
+NAMESPACE_END
+
+#endif