docs: add @intentsolutions/audit-harness npm badge

Both kernel + harness are now official npm packages published with sigstore
provenance (@intentsolutions/core@0.2.0, @intentsolutions/audit-harness@1.1.5).
Surface the harness package alongside core in the umbrella header.

- Jeremy Longshore
intentsolutions.io

Author: jeremylongshore

README.md

@@ -7,6 +7,7 @@
 <p>
   <a href="https://labs.intentsolutions.io/"><img src="https://img.shields.io/badge/live-labs.intentsolutions.io-2c5282" alt="live dashboard"></a>
   <a href="https://www.npmjs.com/package/@intentsolutions/core"><img src="https://img.shields.io/npm/v/@intentsolutions/core?label=%40intentsolutions%2Fcore" alt="core on npm"></a>
+  <a href="https://www.npmjs.com/package/@intentsolutions/audit-harness"><img src="https://img.shields.io/npm/v/@intentsolutions/audit-harness?label=%40intentsolutions%2Faudit-harness" alt="audit-harness on npm"></a>
   <img src="https://img.shields.io/badge/license-Apache--2.0-blue" alt="Apache-2.0">
 </p>