Harden participant and map ownership and validate bounded physical flight

addons/ai/Scripts/Game/ERR/ERR_MortarReadiness.c

@@ -166,6 +166,9 @@ class ERR_MortarReadiness
   }
   if (m_Battery.CountShells() != 27) return ERR_MortarSupplyState.PENDING;
   m_Ready = true;
+  // One physical-ready handoff: HQ already owns/reserves this group, while
+  // Intel must see its actual late-spawned members after finite stock settles.
+  mode.RegisterGroup(group);
   group.ActivateAI();
   foreach (AIAgent readyAgent : agents)
   {