fix: correct default sorting and export desensitization logic

Co-authored-by: aider (openai/DeepSeek-V3.2-Thinking) <aider@aider.chat>

inventory-backend/app/services/inbound/base_service.py

@@ -189,8 +189,8 @@ class MaterialBaseService:
                 else:
                     query = query.order_by(total_avail.desc())
             else:
-                # 默认按规格型号升序
-                query = query.order_by(MaterialBase.spec_model.asc())
+                # 默认排序：优先按总库存数降序，当库存相同时，再按规格型号升序
+                query = query.order_by(total_inv.desc(), MaterialBase.spec_model.asc())
 
             # 分页
             pagination = query.paginate(page=page, per_page=limit, error_out=False)
@@ -594,7 +594,7 @@ class MaterialBaseService:
                 ]
 
                 # 根据用户权限脱敏
-                if user_permissions and 'material_list:*' not in user_permissions:
+                if user_permissions is not None:
                     for field, perm_code in field_to_perm.items():
                         if perm_code not in user_permissions:
                             if field == 'category':