add: add new field to Inventory model

core/apps/wherehouse/migrations/0007_inventory_unit_price.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.2.4 on 2025-08-27 10:23
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('wherehouse', '0006_inventory_is_invalid'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='inventory',
+            name='unit_price',
+            field=models.PositiveBigIntegerField(default=0),
+        ),
+    ]

core/apps/wherehouse/models/inventory.py

@@ -27,6 +27,7 @@ class Inventory(BaseModel):
         related_name='inventories'
     )
     is_invalid = models.BooleanField(default=False)
+    unit_price = models.PositiveBigIntegerField(default=0)
 
     def __str__(self):
         return f'{self.product} in {self.wherehouse}'