feat(merchant): 订单操作流水表与按真实操作人统计

新增 merchant_order_action_log，在结算/撤单/退款/罚单/派单/换打手成功路径写入真实操作人；提供 action-stats / action-operators 接口供经营数据页筛选统计。

Co-authored-by: Cursor <cursoragent@cursor.com>

merchant_ops/migrations/0003_merchantorderactionlog.py

@@ -0,0 +1,46 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('merchant_ops', '0002_merchantstaffmember_merchant_remark'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='MerchantOrderActionLog',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('club_id', models.CharField(db_index=True, default='xq', max_length=16)),
+                ('merchant_id', models.CharField(db_index=True, max_length=7)),
+                ('order_id', models.CharField(db_index=True, max_length=32)),
+                ('action_code', models.PositiveSmallIntegerField(db_index=True, verbose_name='行为码')),
+                ('operator_user_id', models.CharField(db_index=True, max_length=7)),
+                ('operator_type', models.CharField(max_length=16, verbose_name='MERCHANT/STAFF')),
+                ('staff_member_id', models.BigIntegerField(blank=True, db_index=True, null=True)),
+                ('role_code', models.CharField(blank=True, default='', max_length=32)),
+                ('role_name', models.CharField(blank=True, default='', max_length=64)),
+                ('amount', models.DecimalField(blank=True, decimal_places=2, max_digits=12, null=True)),
+                ('leixing_id', models.IntegerField(blank=True, db_index=True, null=True)),
+                ('remark', models.CharField(blank=True, default='', max_length=500)),
+                ('CreateTime', models.DateTimeField(auto_now_add=True, db_index=True)),
+            ],
+            options={
+                'verbose_name': '商家订单操作流水',
+                'db_table': 'merchant_order_action_log',
+            },
+        ),
+        migrations.AddIndex(
+            model_name='merchantorderactionlog',
+            index=models.Index(fields=['merchant_id', 'operator_user_id', '-CreateTime'], name='merchant_or_merchan_op_idx'),
+        ),
+        migrations.AddIndex(
+            model_name='merchantorderactionlog',
+            index=models.Index(fields=['merchant_id', 'action_code', '-CreateTime'], name='merchant_or_merchan_ac_idx'),
+        ),
+        migrations.AddIndex(
+            model_name='merchantorderactionlog',
+            index=models.Index(fields=['merchant_id', 'leixing_id', '-CreateTime'], name='merchant_or_merchan_lx_idx'),
+        ),
+    ]