feat(model): add group field to TransitAgency

this allows us to link a user in the admin interface to a TransitAgency

benefits/core/migrations/0022_transitagency_group.py

@@ -0,0 +1,27 @@
+# Generated by Django 5.0.7 on 2024-08-16 16:08
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("auth", "0012_alter_user_first_name_max_length"),
+        ("core", "0021_rename_eligibilityverifier_enrollmentflow"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="transitagency",
+            name="group",
+            field=models.OneToOneField(
+                blank=True,
+                default=None,
+                help_text="The group of users who can access this TransitAgency.",
+                null=True,
+                on_delete=django.db.models.deletion.PROTECT,
+                to="auth.group",
+            ),
+        ),
+    ]

benefits/core/models.py

@@ -8,6 +8,7 @@
 
 from django.conf import settings
 from django.core.exceptions import ValidationError
+from django.contrib.auth.models import Group
 from django.db import models
 from django.urls import reverse
 
@@ -352,6 +353,14 @@ class TransitAgency(models.Model):
         help_text="The name of the secret containing this agency's client_secret value used to access the TransitProcessor's API.",  # noqa: E501
         default="",
     )
+    group = models.OneToOneField(
+        Group,
+        on_delete=models.PROTECT,
+        null=True,
+        blank=True,
+        default=None,
+        help_text="The group of users who can access this TransitAgency.",
+    )
 
     def __str__(self):
         return self.long_name