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/oaep.h

@@ -0,0 +1,54 @@
+// oaep.h - originally written and placed in the public domain by Wei Dai
+
+/// \file oaep.h
+/// \brief Classes for optimal asymmetric encryption padding
+/// \since Crypto++ 2.1
+
+#ifndef CRYPTOPP_OAEP_H
+#define CRYPTOPP_OAEP_H
+
+#include "cryptlib.h"
+#include "pubkey.h"
+#include "sha.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+/// \brief OAEP padding base class
+/// \since Crypto++ 2.1
+class CRYPTOPP_DLL OAEP_Base : public PK_EncryptionMessageEncodingMethod
+{
+public:
+	bool ParameterSupported(const char *name) const {return strcmp(name, Name::EncodingParameters()) == 0;}
+	size_t MaxUnpaddedLength(size_t paddedLength) const;
+	void Pad(RandomNumberGenerator &rng, const byte *raw, size_t inputLength, byte *padded, size_t paddedLength, const NameValuePairs &parameters) const;
+	DecodingResult Unpad(const byte *padded, size_t paddedLength, byte *raw, const NameValuePairs &parameters) const;
+
+protected:
+	virtual unsigned int DigestSize() const =0;
+	virtual HashTransformation * NewHash() const =0;
+	virtual MaskGeneratingFunction * NewMGF() const =0;
+};
+
+/// \brief OAEP padding
+/// \tparam H HashTransformation derived class
+/// \tparam MGF MaskGeneratingFunction derived class
+/// \sa <a href="http://www.weidai.com/scan-mirror/ca.html#cem_OAEP-MGF1">EME-OAEP</a>, for use with classes derived from TF_ES
+/// \since Crypto++ 2.1
+template <class H, class MGF=P1363_MGF1>
+class OAEP : public OAEP_Base, public EncryptionStandard
+{
+public:
+	static std::string CRYPTOPP_API StaticAlgorithmName() {return std::string("OAEP-") + MGF::StaticAlgorithmName() + "(" + H::StaticAlgorithmName() + ")";}
+	typedef OAEP<H, MGF> EncryptionMessageEncodingMethod;
+
+protected:
+	unsigned int DigestSize() const {return H::DIGESTSIZE;}
+	HashTransformation * NewHash() const {return new H;}
+	MaskGeneratingFunction * NewMGF() const {return new MGF;}
+};
+
+CRYPTOPP_DLL_TEMPLATE_CLASS OAEP<SHA1>;
+
+NAMESPACE_END
+
+#endif