Model preview: AVA2 render-target window on a Vulkan colour target

Port of AVA2's CRenderTarget / GrpRenderTargetTexture / renderTarget module.
The host gains an RGBA8 offscreen colour pass for D3D colour render targets;
mt_preview shows wearable items on every allowed race and monsters with
motions, reached by X+click in the inventory and shop and from the wiki.
Player races are created as TYPE_PC so their parts exist.

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

src/platform/ScriptLib/PythonBoot.cpp

@@ -44,6 +44,7 @@
 #include "UserInterface/PythonSystem.h"
 #include "UserInterface/AbstractApplication.h"
 #include "UserInterface/PythonApplication.h"
+#include "UserInterface/CRenderTargetManager.h"
 #include "EterBase/Timer.h"
 #include "PythonBoot.h"
 #include "../UserInterface/UserInterface.h"
@@ -157,6 +158,7 @@ struct GameSingletons
 	CGuildMarkDownloader kGuildMarkDownloader;
 	CGuildMarkUploader kGuildMarkUploader;
 	CPythonSystem pySystem; // last CPythonApplication member (m_pySystem)
+	CRenderTargetManager renderTargets; // PORT: AVA2 model preview; destroyed first, its models use the rest
 };
 std::unique_ptr<GameSingletons> g_game_singletons;
 bool g_host_hardware_cursor_enabled = false;
@@ -911,6 +913,7 @@ bool run_main_script_body(const char* lpCmdLine, std::string* error)
 	initsafebox();
 	initguild();
 	initServerStateChecker();
+	initRenderTarget(); // PORT: AVA2 model preview
 	init_2v0_gameplay_stubs();
 
 	ClearLogBoxMessage();
@@ -1006,6 +1009,7 @@ namespace PythonBoot
 #include "ChannelScript.inc"
 #include "BossScript.inc"
 #include "VipScript.inc"
+#include "ModelPreviewScript.inc"
 
 static void install_script_module(const char* c_szModule, const char* c_szScript)
 {
@@ -1086,6 +1090,7 @@ bool RunMainScript(const char* lpCmdLine, std::string* error)
 		install_script_module("mt_channel", c_szChannelScript);
 		install_script_module("mt_boss", c_szBossScript);
 		install_script_module("mt_vip", c_szVipScript);
+		install_script_module("mt_preview", c_szModelPreviewScript);
 		if (g_touch_input)
 			install_script_module("mt_mobile_hud", c_szMobileHUDScript);
 	}