fix

problem/migrations/0006_problem_problem_contest_visible_idx.py

@@ -0,0 +1,20 @@
+# Generated by Django 6.0 on 2026-03-30 15:28
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contest', '0002_acmcontestrank_acm_rank_order_idx_and_more'),
+        ('problem', '0005_remove_spj_fields'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name='problem',
+            index=models.Index(fields=['contest', 'visible'], name='problem_contest_visible_idx'),
+        ),
+    ]