chore(seo): disable preferred-sources hub pill until Top Stories eligible

msosorg.com is not yet a Google Top Stories source, so the interactive
pill dead-ends at "No results". Disable addPill() (keep the subtle footer
link, which is harmless and ready). Documented the re-enable steps in
docs/preferred-sources.md so we don't forget.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

preferred-source.js

@@ -58,7 +58,12 @@
     document.head.appendChild(s);
   }
 
-  function init() { addFooterLink(); addPill(); }
+  // NOTE (future to-do): the interactive hub pill (addPill) is intentionally
+  // DISABLED for now. msosorg.com is not yet a Google "Top Stories" source, so
+  // the button dead-ends at "No results". Re-enable addPill() once the site
+  // appears in Top Stories (see docs/preferred-sources.md). The subtle footer
+  // link stays on, ready for when eligibility kicks in.
+  function init() { addFooterLink(); /* addPill(); disabled until Top Stories eligible */ }
   if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', init);
   else init();
 })();