fix(widgets): restore article list rendering and reference styles

tests/widget-system/discovery-reference-contract.test.cjs

@@ -32,8 +32,8 @@ test('term aggregation renders the real SVG use element, total count, and config
   const firstQuery = fixture.aggregation_queries[0];
   assert.equal(firstQuery.posts_per_page, 2);
   assert.equal(firstQuery.no_found_rows, false);
-  assert.deepEqual(firstQuery.category__in, [7]);
-  assert.equal(fixture.aggregation_queries[1].category__in[0], 8);
+  assert.equal(firstQuery.cat, '7');
+  assert.equal(fixture.aggregation_queries[1].cat, '8');
 });
 
 test('category filters keep dropdown and inline terms in separate rendered groups on the ajax-option pipeline', () => {