feat(迁移): 为家庭成员表添加默认成员数据

在家庭成员表中插入一条默认记录，以便系统初始化时使用

core/migrations/0005_add_speaker_fields.py

@@ -25,6 +25,10 @@ class Migration(migrations.Migration):
                 'ordering': ['name'],
             },
         ),
+        migrations.RunSQL(
+            sql="INSERT INTO core_familymember (name, created_at, updated_at) VALUES ('默认成员', datetime('now'), datetime('now'));",
+            reverse_sql="DELETE FROM core_familymember WHERE name='默认成员';",
+        ),
         migrations.AddField(
             model_name='insightrecord',
             name='speaker',