Function detect_in_store 

pub fn detect_in_store(
    store: &WeightStore,
    config: &ModelConfig,
) -> Option<MtpLayout>

detect over a loaded WeightStore.

🪤 On an EP worker the store has already been filtered by expert index, but never by layer — the MTP block’s non-expert tensors are present on every rank, so this answers the same on rank 0 and rank 1.