✨(domains) add support email field on MailDomain

Add new field on MailDomain to allow contact support
if some actions are required to fix domain.

src/backend/mailbox_manager/migrations/0018_maildomain_support_email.py

@@ -0,0 +1,31 @@
+# Generated by Django 5.1.5 on 2025-02-02 21:49
+
+from django.db import migrations, models
+
+
+def fill_support_email(apps, schema_editor):
+    MailDomain = apps.get_model('mailbox_manager', 'MailDomain')
+    for domain in MailDomain.objects.filter(support_email__isnull=True):
+        domain.support_email = "support-regie@numerique.gouv.fr"
+        domain.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mailbox_manager', '0017_alter_maildomain_status'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='maildomain',
+            name='support_email',
+            field=models.EmailField(blank=True, max_length=254, null=True, verbose_name='support email'),
+        ),
+        migrations.RunPython(fill_support_email, reverse_code=migrations.RunPython.noop),
+        migrations.AlterField(
+            model_name='maildomain',
+            name='support_email',
+            field=models.EmailField(max_length=254, verbose_name='support email'),
+        ),
+    ]