Add comment system with models, forms, and UI integration for lessons

courses/migrations/0003_comment_parent.py

@@ -0,0 +1,19 @@
+# Generated by Django 6.0 on 2025-12-10 22:15
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('courses', '0002_comment'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='comment',
+            name='parent',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='replies', to='courses.comment'),
+        ),
+    ]