add has_comment to field formats using primer form

app/forms/custom_fields/details_form.rb

@@ -136,6 +136,14 @@ module CustomFields
         )
       end
 
+      if show_has_comment_field?
+        details_form.check_box(
+          name: :has_comment,
+          label: label(:has_comment),
+          caption: instructions(:has_comment)
+        )
+      end
+
       if show_is_required_field?
         details_form.check_box(
           name: :is_required,
@@ -224,6 +232,10 @@ module CustomFields
       %w[text].include?(model.field_format)
     end
 
+    def show_has_comment_field?
+      model.can_have_comment?
+    end
+
     def show_is_required_field?
       %w[calculated_value bool].exclude?(model.field_format)
     end

spec/features/admin/custom_fields/shared_custom_field_expectations.rb

@@ -150,6 +150,7 @@ RSpec.shared_examples_for "expected fields for the custom field's format", :aggr
   # Form element labels, default English translation in the trailing comment:
   let(:label_name) { I18n.t("attributes.name") } # Name
   let(:label_section) { I18n.t("activerecord.attributes.project_custom_field.custom_field_section") } # Section
+  let(:label_has_comment) { I18n.t("activerecord.attributes.custom_field.has_comment") } # Add a comment text field
   let(:label_is_for_all) { I18n.t("attributes.is_for_all") } # For all projects
   let(:label_admin_only) { I18n.t("activerecord.attributes.custom_field.admin_only") } # Admin-only
   let(:label_searchable) { I18n.t("activerecord.attributes.custom_field.searchable") } # Searchable
@@ -185,6 +186,12 @@ RSpec.shared_examples_for "expected fields for the custom field's format", :aggr
       expect(page).to have_no_label(label_section)
     end
 
+    if type == "Project"
+      expect(page).to have_field(label_has_comment)
+    else
+      expect(page).to have_no_label(label_has_comment)
+    end
+
     if type == "Work package"
       expect(page).to have_field(label_is_filter)
     else