Fix pagination for "Still to vaccinate" filter on patients tab

The "Still to vaccinate" filter uses `Patient#consent_given_and_ready_to_vaccinate`
which returns an Array instead of an ActiveRecord relation due to its complex
filtering logic. This broke pagination since `pagy` expects an ActiveRecord
relation.

Added conditional logic to use `pagy_array` when the result is an Array,
falling back to `pagy` for standard ActiveRecord relations. This ensures
pagination works correctly regardless of the filter type used.

Note: `pagy_array` could be used in both cases, but `pagy` is more performant
for ActiveRecord relations as it doesn't load all records into memory.

Author: jhenderson

app/components/app_patient_search_form_component.rb

@@ -32,7 +32,7 @@ class AppPatientSearchFormComponent < ViewComponent::Base
           <% end %>
         <% end %>
         
-        <% if tallying_enabled? %>
+        <% if tallying_enabled? && show_still_to_vaccinate %>
           <%= f.govuk_check_boxes_fieldset :show_only, multiple: false, legend: { text: "Show only", size: "s" } do %>
             <%= f.govuk_check_box :still_to_vaccinate,
                         1, 0,
@@ -211,7 +211,8 @@ def initialize(
     vaccine_methods: [],
     year_groups: [],
     heading_level: 3,
-    show_aged_out_of_programmes: false
+    show_aged_out_of_programmes: false,
+    show_still_to_vaccinate: false
   )
     @form = form
     @url = url
@@ -226,6 +227,7 @@ def initialize(
     @year_groups = year_groups
     @heading_level = heading_level
     @show_aged_out_of_programmes = show_aged_out_of_programmes
+    @show_still_to_vaccinate = show_still_to_vaccinate
   end
 
   private
@@ -241,7 +243,8 @@ def initialize(
               :vaccine_methods,
               :year_groups,
               :heading_level,
-              :show_aged_out_of_programmes
+              :show_aged_out_of_programmes,
+              :show_still_to_vaccinate
 
   delegate :format_year_group,
            :govuk_button_link_to,

app/controllers/sessions/patients_controller.rb

@@ -15,7 +15,9 @@ def show
       @session.patients.includes(:vaccination_statuses, notes: :created_by)
 
     patients = @form.apply(scope)
-    @pagy, @patients = pagy(patients)
+
+    @pagy, @patients =
+      patients.is_a?(Array) ? pagy_array(patients) : pagy(patients)
   end
 
   private

app/views/sessions/patients/show.html.erb

@@ -16,6 +16,7 @@
           programmes: @session.programmes,
           vaccination_statuses: @statuses,
           year_groups: @session.year_groups,
+          show_still_to_vaccinate: true,
         ) %>
   </div>
 

spec/features/tallying_session_overview_spec.rb

@@ -13,6 +13,10 @@
     and_i_visit_the_session_record_tab
 
     when_i_click_on_each_tally_the_filters_match_the_same_count
+
+    when_i_visit_the_session_record_tab
+    and_i_click_on_the_link_to_view_patients_still_to_vaccinate
+    then_i_should_see_the_patient_that_needs_to_be_vaccinated
   end
 
   def given_a_session_for_flu_is_running_today
@@ -29,6 +33,8 @@ def given_a_session_for_flu_is_running_today
   def and_i_visit_the_session_record_tab
     visit session_path(@session, tallying: true)
   end
+  alias_method :when_i_visit_the_session_record_tab,
+               :and_i_visit_the_session_record_tab
 
   def and_the_tallying_feature_flag_is_enabled
     Flipper.enable(:tallying)
@@ -133,4 +139,14 @@ def when_i_click_on_each_tally_the_filters_match_the_same_count
     expect(page).to have_content("Showing 1 to 1 of 1 children")
     expect(page).to have_content(@patients.fifth.given_name)
   end
+
+  def and_i_click_on_the_link_to_view_patients_still_to_vaccinate
+    click_link "2 children with consent have not been vaccinated yet"
+  end
+
+  def then_i_should_see_the_patient_that_needs_to_be_vaccinated
+    expect(page).to have_content("Showing 1 to 2 of 2 children")
+    expect(page).to have_content(@patients.second.given_name)
+    expect(page).to have_content(@patients.third.given_name)
+  end
 end