Actual socialists, for the whole history of socialism, disagree, but please, don't let that distract you.
> Common ownership and participation in the means of production via democracy is central planning in practice,
When the common ownership is done through the state which directly controls industry, sure, you get central planning. When it's done through democratic worker control of firms, it is no more central planning than when firms are jointly controlled by their capital owners. And there are lots of variations of socialism besides those two.
> It's opposed to the libertarian vision
The idea that socialism is opposed to the libertarian vision is news to libertarian socialists.
I would call what you are describing communism, not socialism. And it's nothing like any major socialist society in existance, because it's unobtainable in practice.
I still contend socialism is about central planning. Common ownership and participation in the means of production via democracy is central planning in practice, since people end up pooling their decision making power.
Representives then implement policies decided by the collective, which all people are subject too.
It's opposed to the libertarian vision, which would be for each person to make more of their own decisions individually, with voting less relevant.