Syndicate (and maybe normal?) MMI brain dies as a mining cyborg during ash storm

[Miraviel]

Issue Description:

When I was a brain in a syndicate MMI and was put into a mining cyborg, I went to mine. Mining cyborgs are immune to ash storms. However, standing in the ash storm, I got the following message: [src]'s MMI flatlines!.

My chassis remained on 100% and I could continue playing.

What did you expect to happen:

For my brain not to fry in a stormproof chassis.

What happened instead:

My brain died and yet I continued playing.

Why is this bad/What are the consequences:

It is confusing.

Steps to reproduce the problem:

1. Put brain into syndicate MMI
2. Put MMI into cyborg
3. Pick mining module
4. Stand in ash storm
5. Watch brain go brrr

When did the problem start happening:

Not sure.

Extra information:

Happened in round 32212 in case you need logs.

[lewcc]

This is kind of an old bug, and one I was pretty sure was fixed. Guess not?

see #13926

[lewcc]

I saw some really weird behavior with this on round 32291. Was able to look into it a bit. I pulled the brain out, it was unresponsive, like it hadn't been activated, but it looked like the client/mind might still have been attached and stuck to the brain. After a certain point, the brain got activated and someone joined into it, but it seemed even more bugged -- despite the blue light showing, interacting with it seemed to restart the rebooting process. By the end of the round, there were about four client mobs in the contents.