A lot of ink gets spilled around this kind of bullshit, when most of communism is focused more directly around anti-capitalism and economic theory.

Effectively, the preventative mechanism against authoritarianism is just democracy, but extended towards parts of the economy which, under capitalism, are conventionally privatized, and thus, are kind of ruled in an authoritarian, "meritocratic" manner. Then this authoritarian capitalism infiltrates and rules the public, democratic portions of society, as we've literally just seen right now with the kind of, explicitly corporate-backed trump administration. I mean, as we've been seeing for maybe the last 80 or so years, right, in a slow ramp up. Which isn't to say the US really had much of a democracy to begin with, it was sort of, designed from the inception to be more of an kind of joint-corporate state ruled by landowners, so in a roundabout way we are actually making america just as it was at inception. You could maybe contrast this situation of authoritarian capitalism with co-operative corporations, which sort of exist at various levels of democratic ownership, and exist to mixed success in a capitalist market context. Or union activity, maybe.

More specifically and directly to answer your question, you'd probably wanna use a Condorcet method, I'm partial to the Schulze method, and you'd maybe wanna set up certain factions of the economy to be voted on by those with domain-specific knowledge so as to not be overly politicized, weaponized, or met with undue interference by other portions of society. You want your railroad guys to be in control of the railroads, basically, rather than having to frame everything for the perhaps relatively uninformed general public. You want to avoid just using the public as a kind of rubber stamp where their approval of your program is contingent on how well you've phrased your proposal, because it just sort of meaninglessly increases costs for no reason. You want engagement to be legitimate rather than taken advantage of by cynical forces. Hopefully, by breaking up these specific sections of society, and giving them agency over their specific domain and nothing else, you can prevent a massive overly centralized and thus more authoritarian hierarchy from arising.

The other criticisms, say, of democracy itself, socialism doesn't quite do as well with. Say, with majoritarian rule slowly shrinking over time, or, the lines and borders that you draw up around particular domains creating a kind of insular and exclusive self-interest of a given class. Which conflicts explicitly with the previous idea, right, of splitting the economy into more and more factions so you can have each of them operate in their domain more efficiently. These would sort of be, more anarchist criticisms of socialism. Communism is sort of, depending on who you ask, some theoretical end state of all this which puts all of these questions out of mind, where everything is as flat as possible.

Realistically, these all tend to be kind of overblown as criticisms anyways, and the much bigger problems stem from the real world circumstances of trying to establish a communist state in a global capitalist hegemony, which is an inherently isolating, hostile, and cruel context. It's hard to do effective democracy in such a context, for the same reason that it's hard to have democracy on a pirate ship when you're getting shot full of holes, while, in other times, the ship would actually be ruled democratically.

I have never seen addressed...

Because you've never actually looked in good faith and without your glaring bias.

it doesn't. Communism hasn't even had a good white paper written about it. Just some random eastern european schizo writing about the rich people or whatever.