//! stderr logging (ADR-0009): all diagnostics on stderr, never stdout.
use SubscriberExt;
use SubscriberInitExt;
use ;
/// Install the tracing subscriber: fmt layer → **stderr**, filtered by
/// `RUST_LOG` (default `warn`). Codex-exec's exact setup
/// (`fmt::layer().with_writer(std::io::stderr).with_filter(env_filter)`).