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>

tests/port/port_fake_login_server_main.cpp

@@ -0,0 +1,34 @@
+// The fake 40250 auth + game server of port_login_flow_test as its own process, for runs that drive the
+// real client from Godot (scripts/python_game_render_test.sh). Prints "ports <auth> <game>" once it
+// listens and serves until SIGTERM or SIGINT; the milestones go to stderr on the way out.
+#include "port_login_flow_server.h"
+
+#include <csignal>
+#include <cstdio>
+#include <unistd.h>
+
+static volatile std::sig_atomic_t g_stop = 0;
+
+static void on_signal(int) { g_stop = 1; }
+
+int main()
+{
+	std::signal(SIGTERM, on_signal);
+	std::signal(SIGINT, on_signal);
+	FakeLoginServer server;
+	if (!server.Start())
+	{
+		std::fprintf(stderr, "port_fake_login_server: cannot listen on loopback\n");
+		return 1;
+	}
+	std::printf("ports %d %d\n", server.AuthPort(), server.GamePort());
+	std::fflush(stdout);
+	while (!g_stop)
+		pause();
+	std::fprintf(stderr, "port_fake_login_server events:");
+	for (const auto& e : server.Events())
+		std::fprintf(stderr, " %s", e.c_str());
+	std::fprintf(stderr, "\nport_fake_login_server error: %s\n", server.Error().c_str());
+	server.Stop();
+	return server.Failed() ? 1 : 0;
+}