CLDC-4352: Update building height class hint text as dropdown (#3335)

* CLDC-4352: update hint text as dropdown

* CLDC-4352: update spec

* CLDC-4352: refactoring

app/models/form/sales/questions/building_height_class.rb

@@ -3,6 +3,7 @@ class Form::Sales::Questions::BuildingHeightClass < ::Form::Question
     super
     @id = "buildheightclass"
     @type = "radio"
+    @top_guidance_partial = "building_height_class"
     @answer_options = ANSWER_OPTIONS
     @question_number = get_question_number_from_hash(QUESTION_NUMBER_FROM_YEAR)
   end

app/views/form/guidance/_building_height_class.html.erb

@@ -0,0 +1,5 @@
+<div class="govuk-body">
+  <%= govuk_details(summary_text: I18n.t("forms.#{@log.form.start_date.year}.sales.guidance.building_height_class.title")) do %>
+    <%= I18n.t("forms.#{@log.form.start_date.year}.sales.guidance.building_height_class.content").html_safe %>
+  <% end %>
+</div>

config/locales/forms/2026/sales/guidance.en.yml

@@ -55,3 +55,12 @@ en:
             title: "What is a UPRN?"
             content: "<p>The Unique Property Reference Number (UPRN) is a unique number system created by Ordnance Survey and used by housing providers and various industries across the UK. An example is 0010457355.</p>
               <p>The UPRN may not be the same as the property reference assigned by your organisation.</p>"
+
+          building_height_class:
+            title: "What do these classifications mean?"
+            content: "<p>High-rise residential buildings are those containing 2 or more residential units and either:</p>
+                      <ul class=\"govuk-list govuk-list--bullet\">
+                        <li>have 7 or more stories</li>
+                        <li>are at least 18 metres in height</li>
+                      </ul>
+                      <p>If unsure, answer based on the number of storeys.</p>"

config/locales/forms/2026/sales/property_information.en.yml

@@ -60,10 +60,10 @@ en:
             question_text: "What type of unit is the property?"
 
           buildheightclass:
-            page_header: ""
+            page_header: "Building height classification"
             check_answer_label: "Building height classification"
             check_answer_prompt: ""
-            hint_text: "High-rise residential buildings are those containing 2 or more residential units and either have 7 or more storeys or are at least 18 metres in height. If unsure, answer based on the number of storeys."
+            hint_text: ""
             question_text: "What is the building height classification?"
 
           builtype:

spec/models/form/sales/questions/building_height_class_spec.rb

@@ -36,4 +36,8 @@ RSpec.describe Form::Sales::Questions::BuildingHeightClass, type: :model do
   it "has the correct question_number" do
     expect(question.question_number).to eq(17)
   end
+
+  it "has correct guidance partial" do
+    expect(question.top_guidance_partial).to eq("building_height_class")
+  end
 end