CLDC-4202: Extract person question count to the form definition

app/models/form.rb

@@ -357,4 +357,12 @@ class Form
   def start_year_2026_or_later?
     start_date && start_date.year >= 2026
   end
+
+  def person_question_count
+    if form.start_year_2026_or_later?
+      5
+    else
+      4
+    end
+  end
 end

app/models/form/lettings/questions/age.rb

@@ -29,13 +29,7 @@ class Form::Lettings::Questions::Age < ::Form::Question
                              27
                            end
 
-    person_question_count = if form.start_year_2026_or_later?
-                              5
-                            else
-                              4
-                            end
-
-    base_question_number + (person_question_count * @person_index)
+    base_question_number + (form.person_question_count * @person_index)
   end
 
   def hint_text

app/models/form/lettings/questions/person_partner.rb

@@ -31,13 +31,7 @@ class Form::Lettings::Questions::PersonPartner < ::Form::Question
                              28
                            end
 
-    person_question_count = if form.start_year_2026_or_later?
-                              5
-                            else
-                              4
-                            end
-
-    base_question_number + (person_question_count * @person_index)
+    base_question_number + (form.person_question_count * @person_index)
   end
 
   def derived?(log)

app/models/form/lettings/questions/person_working_situation.rb

@@ -67,12 +67,6 @@ class Form::Lettings::Questions::PersonWorkingSituation < ::Form::Question
                              31
                            end
 
-    person_question_count = if form.start_year_2026_or_later?
-                              5
-                            else
-                              4
-                            end
-
-    base_question_number + (person_question_count * @person_index)
+    base_question_number + (form.person_question_count * @person_index)
   end
 end