Function encode_pooled 

pub fn encode_pooled(
    shared_secret: &[u8],
    plaintext: &[u8],
    pool: &EntropyPool,
) -> Result<KkPacket>

Encode plaintext using a pre-warmed EntropyPool instead of calling entropy::gather() on every invocation.

Identical semantics to encode, but the entropy snapshot is drawn from the pool (near-zero latency) rather than generated on the spot.