feat: write all logs to stderr (vs stdout)

Currently, all logs are being written to stdout. This breaks convention for CLI apps that might want to use stdout for, well, application output (not diagnostic stuff).

crates/core/machine/src/utils/logger.rs

@@ -37,6 +37,7 @@ pub fn setup_logger() {
                     .with_thread_names(false)
                     .with_env_filter(env_filter)
                     .with_span_events(FmtSpan::CLOSE)
+                    .with_writer(std::io::stderr)
                     .finish()
                     .init();
             }