I like this, but is there another option other than human? if it's only human or bot, maybe the kind field could be only {bot:"type of bot"}, if other types then yes, like you have is perfect.
Discussion
type of bot could just be another field if that was ever needed. It could also just be {bot:true} to keep things simple?
if the filed bot is present, then it's true, so might as well take use the other field for something productive. but as you had initially is more than a good fit for anything, that might not be bots, and we can always have a {type:"my bot"} if needed.
type:bot on kind0 works for me, #[3] ?
definitely agree this is better than nothing, and am on board. however not completely happy with this long term as you have to query the posts, and then query all post's pubkeys to ascertain whether its a bot to be filtered.
damn we need edits working