Function export_value 

pub fn export_value(
    vault_root: &Path,
    requested_path: &Path,
    format: Format,
    value: &Value,
) -> Result<PathBuf>

Export an arbitrary JSON-serializable value to a file under the vault root.

JSON and YAML accept any shape. CSV and XLSX only work when the value is tabular — an array of objects, an array of scalars, or a single object — and return an error for anything else.