fix: WMaterialCreateSerializer 所有字段设为必填

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/wpm/serializers.py

@@ -211,6 +211,12 @@ class WMaterialCreateSerializer(CustomModelSerializer):
     class Meta:
         model = WMaterial
         fields = ['material', 'count', 'batch', 'mgroup']
+        extra_kwargs = {
+            'material': {'required': True},
+            'count': {'required': True},
+            'batch': {'required': True},
+            'mgroup': {'required': True, 'allow_null': False},
+        }
 
     def validate(self, attrs):
         attrs['belong_dept'] = attrs['mgroup'].belong_dept