Function build_single_file_tar_cmd

crates/openshell-cli/src/ssh.rs:1211–1217

Build the `tar cf - -C -- ` command used to wrap a single sandbox-side file for download. The trailing `--` is required: a sandbox-side file whose basename starts with `-` (e.g. `--checkpoint-action=...`) would otherwise be parsed by GNU tar as an option rather than a member to archive.

(parent: &str, basename: &str)

/// with `-` (e.g. `--checkpoint-action=...`) would otherwise be parsed by GNU
/// tar as an option rather than a member to archive.
fn build_single_file_tar_cmd(parent: &str, basename: &str) -> String {
    format!(
        "tar cf - -C {parent} -- {name}",
        parent = shell_escape(parent),
        name = shell_escape(basename),
    )
}

async fn sandbox_sync_down_file(
    session: &SshSessionConfig,