rlmesh::predict_seed
The per-predict sampling seed: a reproducible mix of the episode's reset seed and the re-plan ordinal within that episode.
fn predict_seed(episode_seed: i64, predict_index: u64) -> i64A stochastic policy seeded once per episode cannot be reproduced under
interleaving — another episode’s forward advances the same global
generators between two of ours. Deriving a fresh seed per predict from
(episode_seed, predict_index) makes each forward reproducible on its
own, independent of what ran between. The SDK stamps the result on the
predict context as predict_seed; a model can also derive it with this
function.
FNV-1a over the seed and the ordinal, masked to 32 bits — the narrow range every framework’s seeding API accepts.