Function place_downloaded_file

crates/openshell-cli/src/ssh.rs:1264–1292

Move a single file extracted by `stream_sandbox_tar` into its final position on the host. `staging_dir` must contain a single regular-file entry named `source_basename` (the wrapper produced by `tar cf - -C `). The entry is renamed onto `final_path`, atomically when `staging_dir` is on the same filesystem. Refuses to overwrite an existing directory at `final_path` to match `cp` beh

(
    staging_dir: &Path,
    source_basename: &str,
    final_path: &Path,
)

/// on the same filesystem. Refuses to overwrite an existing directory at
/// `final_path` to match `cp` behaviour.
fn place_downloaded_file(
    staging_dir: &Path,
    source_basename: &str,
    final_path: &Path,
) -> Result<()> {
    let staged_file = staging_dir.join(source_basename);
    let staged_meta = fs::symlink_metadata(&staged_file)
        .into_diagnostic()
        .wrap_err("downloaded archive did not contain the expected entry")?;
    if !staged_meta.is_file() {
        return Err(miette::miette!(
            "downloaded entry '{source_basename}' is not a regular file"
        ));
    }

    if let Ok(existing) = fs::symlink_metadata(final_path)
        && existing.is_dir()
    {
        return Err(miette::miette!(
            "cannot overwrite directory '{}' with downloaded file",
            final_path.display()
        ));
    }

    fs::rename(&staged_file, final_path)
        .into_diagnostic()
        .wrap_err_with(|| format!("failed to rename into '{}'", final_path.display()))?;
    Ok(())
}

async fn sandbox_sync_down_directory(
    session: &SshSessionConfig,