Add HTML5 metadata preview summary

services/api-server/src/api_server/html5.py

@@ -911,6 +911,7 @@ def render_html5_metadata_preview_result(
         <span>+{escape(str(added))} / -0</span>
         <small>{escape(next_version_id or "version preview unavailable")}</small>
       </article>
+      {_authoring_result_summary("changed" if changed else "unchanged", diff, checks)}
       <div class="check-list">{check_rows}</div>
       <div class="diff-list">{diff_rows}</div>
       {apply_form}

services/api-server/tests/test_api.py

@@ -3017,6 +3017,9 @@ def test_authoring_metadata_object_preview_and_apply(tmp_path: Path):
     assert html5_preview.status_code == 200
     assert "text/html" in html5_preview.headers["content-type"]
     assert "data-html5-metadata-preview-result" in html5_preview.text
+    assert "data-html5-authoring-result-summary" in html5_preview.text
+    assert "changed" in html5_preview.text
+    assert "diff lines" in html5_preview.text
     assert "data-html5-metadata-apply-form" in html5_preview.text
     assert f'hx-post="/html5/projects/{project_id}/authoring/apply-metadata-object"' in html5_preview.text
     assert "Документ.ЗаявкаНаЗакупкуHtml5" in html5_preview.text