feat: publisher, local business and home crumb settings

- Publisher and Local business tabs with the C20 refusals (sameAs lines,
  person as local business, address, times, country, coordinates)
- the publisher node from the settings, as an Organization, a Person or
  the chosen local business type with address, geo and opening hours
- P8 publisher preview with Google's required and recommended findings
  (classes/schema Validate)
- the home crumb name on the General tab; every new key in the settings
  API and seo_update_settings

controllers/settings.go

@@ -107,8 +107,8 @@ type stagingView struct {
 }
 
 // PartialData serves the staging callout, shown outside production where
-// every page is noindex whatever the settings say (D-22), and the P3
-// placeholder table.
+// every page is noindex whatever the settings say (D-22), the P3
+// placeholder table and the P8 publisher preview.
 func (c settingsAdminController) PartialData(ctx context.Context, name string, _ any) (any, error) {
 	switch name {
 	case "staging":
@@ -119,6 +119,12 @@ func (c settingsAdminController) PartialData(ctx context.Context, name string, _
 			return nil, err
 		}
 		return svc.Placeholders(ctx), nil
+	case "publisher_preview":
+		svc, err := classes.NewService(appOf(c.app))
+		if err != nil {
+			return nil, err
+		}
+		return svc.PublisherPreview(ctx)
 	}
 	return nil, nil
 }