feat: 保存 SQL 题时自动生成 sql_display 展示数据

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

problem/migrations/0012_problem_sql_display.py

@@ -0,0 +1,18 @@
+# Generated by Django 6.0.4 on 2026-07-03 07:14
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('problem', '0011_problem_sql_config'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='problem',
+            name='sql_display',
+            field=models.JSONField(blank=True, default=None, null=True),
+        ),
+    ]