Handle errors at the application boundary

Library APIs return OrthoResult<T>, whose error is an Arc<OrthoError>. Propagate it while loading, then render or map it where the application owns the user experience:

use ortho_config::{OrthoConfig, OrthoError};
use serde::Deserialize;

#[derive(Debug, Deserialize, OrthoConfig)]
struct Config {
    port: u16,
}

fn main() {
    match Config::load_from_iter(["acme", "--port", "not-a-number"]) {
        Ok(config) => println!("port={}", config.port),
        Err(error) => match error.as_ref() {
            OrthoError::CliParsing(clap_error) => eprintln!("{clap_error}"),
            other => eprintln!("configuration error: {other}"),
        },
    }
}

Preserve clap's display-only exits for --help and --version; use is_display_request when a wider application error layer needs to distinguish them. OrthoError::try_aggregate combines independent validation failures without inventing an error for an empty collection. The result extension traits OrthoResultExt, OrthoMergeExt, and ResultIntoFigment keep conversions explicit at integration boundaries.