feat: new module: 'shipment', new signal when process was finished

shipment/migrations/0002_salesitem_shipment_nullable.py

@@ -0,0 +1,19 @@
+# Generated by Django 5.2.8 on 2026-01-13 10:02
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('shipment', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='salesitem',
+            name='shipment',
+            field=models.ForeignKey(blank=True, help_text='为空表示待分配', null=True, on_delete=django.db.models.deletion.CASCADE, related_name='items', to='shipment.shipment', verbose_name='出货单'),
+        ),
+    ]