Function check_actor 

pub(crate) fn check_actor(
    state: &AppState,
    caller: Option<&Caller>,
    site: ActorSite,
    actor: Option<&str>,
)

Count actor against the caller’s row at site. A no-op for an Unattributed caller. Never fails and is never awaited: the store reads run detached on the blocking pool (inline under test, so tests can read the counters right after the request).