Function ml_dsa_sign 

fn ml_dsa_sign(
    keypair: &PqdsaKeyPair,
    m_prime: &[u8],
    out: &mut [u8],
) -> Result<(), Opaque>

Signs m_prime with ML-DSA-65 into out, which must hold at least ML_DSA_65_SIGNING.signature_len() bytes.

STANDARD-DEVIATION: the standard signs with mldsa_ctx = LABEL, but aws_lc_rs exposes no ML-DSA context, so the empty ML_DSA_CTX is used (guarded by its compile-time assertion). See the module docs for the conformance path.