Constant ML_DSA_CTX 

const ML_DSA_CTX: &[u8] = b"";

Context passed to the underlying ML-DSA primitive.

This is the sole deviation from the standard, which uses LABEL here. aws_lc_rs’s ML-DSA API currently exposes no context parameter, so we use the empty context. Setting this to LABEL (once a context-capable backend exists) is what makes signatures standard-conformant.