Targeting AI choosing bad targets

[Stuart1998]

Good target, generally: unit that's shooting you
Bad target: unit that's not

If an enemy unit that was shooting at a given unit leaves its range and thus can't shoot anymore, the targeting AI should switch to a unit that is still shooting at it. This doesn't happen right now, a unit will keep targeting the same enemy unit until its left its own range.

Bizarrely, sometimes even after that unit dies or leaves range, the targeting AI will choose another unit that's also currently firing over other units that are. These problems make riots significantly easier to overrun than they'd be with better targeting.

Additionally, currently units seem to prioritize nanoframes over cons, automatically switching to targeting nanoframes over cons they were already shooting at. This is bad; there are times when you want to target the nanoframe over the con but they're rare enough that you can just manually target them; cons should be targeted over nanoframes. I think I've even seen situations where units prioritize nanoframes over units that are in range and actively shooting at them.

[Stuart1998]

https://zero-k.info/Battles/Detail/2055220 has a good example of both of these issues. At 3:07 my Reaver begins firing at the closest kodachi to it. At 3:10 that kodachi dies and 3 other kodachis have entered range, but a 4th is not yet in range. The reaver targets this most distant kodachi to it over the three that are firing at it. In the time it takes it to kill that kodachi, the other three kodachi have all but destroyed it, and they finish the job before it can fire another shot.