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/sha256_armv4.h

@@ -0,0 +1,23 @@
+/* Header file for use with Cryptogam's ARMv4 SHA1.    */
+/* Also see http://www.openssl.org/~appro/cryptogams/  */
+/* https://wiki.openssl.org/index.php/Cryptogams_SHA.  */
+
+#ifndef CRYPTOGAMS_SHA256_ARMV4_H
+#define CRYPTOGAMS_SHA256_ARMV4_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Crypto++ modified cryptogams_sha256_block_data_order to pass caps as a parameter. */
+/* Also see https://github.com/weidai11/cryptopp/issues/846.             */
+void cryptogams_sha256_block_data_order(void *state, const void *data, size_t blocks);
+
+/* Cryptogams arm caps */
+#define CRYPTOGAMS_ARMV7_NEON (1<<0)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* CRYPTOGAMS_SHA256_ARMV4_H */