Fix: don’t require attendance when session registration is disabled

A recent change (e9290c8) added a patient must be attending today validation
to the vaccination recording flow to prevent recording vaccinations for patients
marked absent. That validation looked for an `AttendanceRecord` and treated missing
record the same as not attending.

In sessions where registration is turned off, attendance records are not expected
to exist, so vaccination recording was blocked even though registration is optional
for that session.

Author: jhenderson

app/models/draft_vaccination_record.rb

@@ -501,6 +501,7 @@ def delivery_site_matches_delivery_method
   def validate_patient_attendance
     return unless new_record?
     return unless session&.today?
+    return unless session&.requires_registration?
     return if patient.blank?
 
     attendance_record =

spec/models/draft_vaccination_record_spec.rb

@@ -128,6 +128,29 @@
       it { should validate_length_of(:notes).is_at_most(1000).on(:update) }
     end
 
+    context "when registration is disabled for the session" do
+      let(:session) do
+        create(
+          :session,
+          team:,
+          programmes: [programme],
+          requires_registration: false
+        )
+      end
+
+      let(:patient) { create(:patient, session:) }
+      let(:attributes) { valid_administered_attributes }
+
+      before { draft_vaccination_record.wizard_step = :confirm }
+
+      it "does not require an attendance record to record a vaccination" do
+        expect(draft_vaccination_record.save(context: :update)).to be(true)
+        expect(draft_vaccination_record.errors[:base]).not_to include(
+          "Child is marked as not attending this session. Mark them as attending to record a vaccination."
+        )
+      end
+    end
+
     context "when the patient is marked not attending" do
       let(:attributes) { valid_administered_attributes }
       let(:patient) { create(:patient, session:) }