2V2-e.2: Godot consumer of the 3D draw commands, offline screenshot

python_3d_surface.gd turns RenderGame's recorded draws into meshes under a
camera read back from SetPerspective; textures come from the 40250 packs.
GetFarClip and the CMapManager ctor ported verbatim. Until the environment
is ported, lit draws with no light/ambient are shown unshaded (stand-in).
script/python_game_render_test.sh runs system.py login -> select -> game
against port_fake_login_server (or --live via MT_LIVE_*) and screenshots.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

extension/tests/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 (script/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;
+}