Function read_rw_server_params 

pub fn read_rw_server_params<R: Read>(
    r: &mut R,
    want: usize,
    peer: &str,
) -> Result<Vec<CacheServerParams>>

RW-blade dialect (KV overflow / snapshots): read the peer’s [u8 n] echo (must equal the negotiated want; deliberately NOT bounded to 8 — the RO dialect’s 1..=8 bound is its own, and unifying validation would change accepted wire inputs) followed by n CacheServerParams.