Function rs_shard_esp

crates/ffi/src/kernel.rs:1928–1955

(
  esp_path: LeanString<LeanBorrowed<'_>>,
  num_shards: LeanString<LeanBorrowed<'_>>,
  balance_pct: LeanString<LeanBorrowed<'_>>,
  parallelism: LeanString<LeanBorrowed<'_>>,
  out_path: LeanString

      tracing_texray::rss_sampler::reset_peak_tree_rss();
      let t = Instant::now();
      let selected = if skip_deps {
        vec![ctx.kernel_work[*item_idx].clone()]
      } else {
        closure_work_items(&ctx, &[*item_idx])
      };
      let (work, addrs) = index_anon_work(selected);
      let total = addrs.len();
      let results = match run_anon_checks_parallel(
        Arc::clone(&ctx.env),
        work,
        addrs.clone(),
        quiet,
        None,
      ) {
        Ok(r) => r,
        Err(msg) => {
          return build_uniform_error(total, &format!("[thread] {msg}"));
        },
      };
      let failed = results.iter().filter(|r| r.is_err()).count();
      let secs = t.elapsed().as_secs_f64();
      let tput = if secs > 0.0 {
        f64::from(u32::try_from(total).unwrap_or(u32::MAX)) / secs
      } else {
        0.0
      };
      let status = if failed > 0 {
        ix_bench::Status::Rejected
      } else {
        ix_bench::Status::Ok
      };