port: FlyingData/Instance/ObjectManager/FlyTrace + effect/fly modules (batch 2 P1)

Verbatim copies of the 40250 flying-object units and the effect/fly
Python modules replace the pending CFlyingManager stand-in and the two
module stubs; initeffect/initfly run after initnet as in 40250 and the
flying manager gets the background as its map manager.
CMapManager::GetTerrainHeight is added over the native height tiles.
login_flow checks playersettingmodule registered the indexed fly data.

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

extension/tests/port_login_flow_test.cpp

@@ -45,6 +45,8 @@
 #include "GameLib/RaceManager.h"
 #include "GameLib/RaceData.h"
 #include "GameLib/RaceMotionData.h"
+#include "GameLib/FlyingData.h"
+#include "GameLib/FlyingObjectManager.h"
 #include "UserInterface/StdAfx.h"
 #include "UserInterface/PythonCharacterManager.h"
 #include "UserInterface/InstanceBase.h"
@@ -433,6 +435,16 @@ int main(int argc, char** argv)
 			CHECK(blocked > 0);
 		}
 
+		// playersettingmodule.py registered the indexed fly data (effect.RegisterIndexedFlyData → CFlyingManager →
+		// CFlyingData::LoadScriptFile): the .msf parses, and registering the name again finds it already present.
+		{
+			const char* msf = "d:/ymir work/effect/etc/gathering/ga_piece_yellow_small2.msf";
+			CFlyingData* data = CFlyingData::New();
+			CHECK(data->LoadScriptFile(msf));
+			CFlyingData::Delete(data);
+			CHECK(!CFlyingManager::Instance().RegisterFlyingData(msf));
+		}
+
 		// 8. (批次 2V3) Click-to-move: a left click on the ground below the actor reaches game.GameWindow's
 		//    OnMouseLeftButtonDown → player.SetMouseState(MBT_LEFT, MBS_PRESS); CPythonPlayer picks the ground
 		//    through the cursor ray (CScreen::SetCursorPosition → CPythonBackground::GetPickingPoint) and the