Function read_state_value_blocking 

pub fn read_state_value_blocking<R>(reader: &mut R) -> Result<Option<Value>>
where
    R: Read,

Blocking sibling of read_state_value for the sync heartbeat-enrichment path, which reads one snapshot under a socket read timeout rather than on a tokio task. Shares the exact framing + decode core (v2_body_len + decode_state_body); only the byte pump differs.