Function subject_of_cover

zisk/host/src/main.rs:691–699

The canonical subject root a leaf guest commits for a chunk that certifies `cover` (its `covered()` target addresses): `merkle_root_canonical` over the addresses, exactly as the guest computes it. Used host-side to re-derive the expected per-child subject *from the env* (not from the proof) so the final aggregate's committed subject can be checked against the env it should cover.

(cover: &[[u8; 32]])

  let parsed: Vec<(String, IxonEnv, Vec<AnonWorkItem>)> = inputs
    .iter()
    .map(|ixe| {
      let label = ixe
        .as_ref()
        .map(|p| p.display().to_string())
        .unwrap_or_else(|| "<empty env>".to_string());
      let bytes = load_env_bytes(ixe.as_ref());
      let env =
        IxonEnv::get_anon(&mut &bytes[..]).expect("invalid Ixon environment");
      let work = build_anon_work(&env).expect("build_anon_work");
      (label, env, work)
    })
    .collect();