BTHLABS-61: Service layer refactoring

A journey to fix `ValidationError` in Pocket imports turned service
layer refactoring :D

services/backend/tests/ui/views/associations/test_unstar.py

@@ -54,6 +54,45 @@ def test_ok_htmx(authenticated_client: Client,
     assert result.context['association'].target.pk == starred_association_out.target.pk
 
 
+@pytest.mark.django_db
+def test_archived(authenticated_client: Client,
+                  archived_association_out,
+                  ):
+    # When
+    result = authenticated_client.get(
+        reverse('ui.associations.unstar', args=(archived_association_out.pk,)),
+    )
+
+    # Then
+    assert result.status_code == http.HTTPStatus.NOT_FOUND
+
+
+@pytest.mark.django_db
+def test_deleted(authenticated_client: Client,
+                 deleted_association_out,
+                 ):
+    # When
+    result = authenticated_client.get(
+        reverse('ui.associations.unstar', args=(deleted_association_out.pk,)),
+    )
+
+    # Then
+    assert result.status_code == http.HTTPStatus.NOT_FOUND
+
+
+@pytest.mark.django_db
+def test_not_found(authenticated_client: Client,
+                   null_uuid,
+                   ):
+    # When
+    result = authenticated_client.get(
+        reverse('ui.associations.unstar', args=(null_uuid,)),
+    )
+
+    # Then
+    assert result.status_code == http.HTTPStatus.NOT_FOUND
+
+
 @pytest.mark.django_db
 def test_other_account_association(authenticated_client: Client,
                                    other_account_starred_association_out,