feat: add enterprise identity and channel integrations

backend/apps/channels/migrations/0002_channelmessage_customer_reply.py

@@ -0,0 +1,40 @@
+import django.db.models.deletion
+from django.db import migrations, models
+from django.db.models import Q
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("channels", "0001_initial"),
+        ("tickets", "0014_customerreplytask_channel_approval"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="channelmessage",
+            name="customer_reply_task",
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.PROTECT,
+                related_name="channel_messages",
+                to="tickets.customerreplytask",
+            ),
+        ),
+        migrations.AddField(
+            model_name="channelmessage",
+            name="reply_revision",
+            field=models.PositiveIntegerField(blank=True, null=True),
+        ),
+        migrations.AddConstraint(
+            model_name="channelmessage",
+            constraint=models.UniqueConstraint(
+                fields=("customer_reply_task", "reply_revision"),
+                condition=Q(
+                    direction="outbound",
+                    customer_reply_task__isnull=False,
+                ),
+                name="unique_channel_reply_revision",
+            ),
+        ),
+    ]