Fix Ender Dragon damage, End portal transition, and End Poem crash

Dragon melee damage: reassign sub-entity IDs to be sequential from
the parent entity ID in ServerLevel::entityAdded(), so the client's
offset-based ID calculation matches the server. Previously the server's
smallId pool allocated non-sequential IDs, causing melee attacks to
target entity IDs the server didn't recognize.

End portal transition: ensure the player entity is always added to the
new level when transitioning from The End, not just for non-End
dimensions. The addEntity call was previously gated behind a
lastDimension != 1 check that also excluded it from End exits.

End Poem crash: bounds-check the WIN_GAME event's player index before
accessing localplayers[], with a fallback to prevent null dereference
when the server sends an out-of-range index.

Minecraft.Client/PlayerConnection.cpp

@@ -816,9 +816,7 @@ void PlayerConnection::handleInteract(shared_ptr<InteractPacket> packet)
 		{
 			if ((target->GetType() == eTYPE_ITEMENTITY) || (target->GetType() == eTYPE_EXPERIENCEORB) || (target->GetType() == eTYPE_ARROW) || target == player)
 			{
-				//disconnect("Attempting to attack an invalid entity");
-				//server.warn("Player " + player.getName() + " tried to attack an invalid entity");
-				return;
+					return;
 			}
 			player->attack(target);
 		}