Configurable enemy distance threshold

[DataBeaver]

I wanted to use the logistic network interface to automatically collect alien ore at my walls. Unfortunately it didn't work out of the box. Some investigation revealed this to be due to enemy proximity. The mod description says it doesn't mark items if there are enemies within the construction zone, and there are none, but looking at the code it looks like the distance used is actually 1.5 times the construction zone radius plus 40 tiles. With my current mods (Rampant in particular) and progress in the save (no artillery yet) I'm unable to consistently keep enemies far enough.

It would be nice if I could configure the distance where enemies are considered a danger and/or set an area where items are collected regardless of enemies. The bots will go out to repair my walls even while enemies are attacking anyway, so preventing them from collecting items inside the walls doesn't improve safety. If you can figure out a way to automatically detect where the wall is, that would be super cool, but I expect it would cost too much performance to be practical.

(Thread on mod portal: https://mods.factorio.com/mod/Nanobots/discussion/62897fa8432c175b99b16692)

[Nexela]

I am thinking a biter signal.
When no biter signal is present use construction zone
When it is present use construction zone + signal amount

[Nexela]

Related #127