Expand description
Machine-readable test reports for harn test.
User and conformance suites both feed the same writer so the JUnit
XML and --json-out payloads have a single source of truth. CI
systems get a uniform schema; performance audits get per-file and
per-test timing without scraping ANSI-coloured terminal output.
The writers fail loudly: a missing or unwritable destination returns an error so the CLI can exit non-zero rather than silently succeed (issue #2146).