Optimistic UI #278

what would the failure mode here look like? some approaches i've seen: bsky's client applications tend to ignore errors in some cases (liking a post without internet access just fails without notice), but some other actions fail with a toast notification.

my opinion on this is that we avoid htmx magic, but instead make the atproto bits of the handler asynchronous:

Handler() {
    // do db work
    db.Set(newState)
    go pds.Set(newState) onError { db.Set(oldState) }
}

to notify the user of a failure, we could use htmx-wss to send a toast notification. the trickier part is to revert the client state update, for example: starring a repo when the PDS is down would require us to send a toast and "unstar" the repo so that the user can try again.