pub async fn webserver_test(
sandbox: &Path,
cargo_target_dir: Option<&Path>,
build_timeout: Duration,
serve_timeout: Duration,
) -> WebserverResultExpand description
2026-09-26: Builds the project in release, runs it on a reserved port and
checks that /ping answers pong within serve_timeout. Every failure is
reported in WebserverResult::error, not as an Err.