port: PythonItem + item module (batch 2 P3-b)

Verbatim 40250 CPythonItem and the item Python module replace the
pending stand-in and the module stub; CPythonApplication::Create calls
m_pyItem.Create() in 40250 order. itemGetIconImage returns its handle
through Py_BuildPointer (the ILP32 int truncated it and wndMgr.SetSlot
crashed on the live inventory). CMapManager::GetNormal evaluates
CTerrain::CalculateNormal on the native height tile; the item text-tail
members stay stubs, Pick answering -1 like an empty tail map.

The fake server drops vnum 19 next to the actor at entergame and answers
CG_ITEM_PICKUP with GC_ITEM_GROUND_DEL; login_flow picks it up through
player.PickCloseItem and checks item.SelectItem(19).

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

extension/src/platform/UserInterface/PythonApplication.cpp

@@ -7,6 +7,7 @@
 #include "EterLib/ResourceManager.h"
 #include "UserInterface/PythonNetworkStream.h"
 #include "UserInterface/AccountConnector.h"
+#include "UserInterface/PythonItem.h"
 #include "UserInterface/PythonSkill.h"
 #include "UserInterface/PythonNonPlayer.h"
 #include "GameLib/ItemManager.h"
@@ -119,6 +120,10 @@ bool CPythonApplication::Create(PyObject*, const char*, int, int, int)
 		PyErr_SetString(PyExc_RuntimeError, "CREATE_NETWORK");
 		return false;
 	}
+
+	// 40250 m_pyItem.Create() (PythonApplication.cpp:1253): registers dropitem.mse with CEffectManager,
+	// still a platform stub.
+	CPythonItem::Instance().Create();
 	return true;
 }
 // 40250 PythonApplication.cpp:105