feat(product_management): 接入产品层

- app/pipeline_app.py: load_product_management()，置于资源模块之后
  (产品层通过 env.product_interface 调 account_resource/storage_resource)
- 打通资源→产品→定价→折扣→出账链路

app/pipeline_app.py

@@ -86,6 +86,11 @@ def init():
         from storage_resource.init import load_storage_resource
     except ImportError:
         def load_storage_resource(): pass
+    # product_management：产品层，通过 env.product_interface 调资源模块
+    try:
+        from product_management import load_product_management
+    except ImportError:
+        def load_product_management(): pass
 
     set_globalvariable()
     ServerEnv().get_module_dbname = get_module_dbname
@@ -103,6 +108,7 @@ def init():
     load_unipay()
     load_account_resource()
     load_storage_resource()
+    load_product_management()   # 产品层：依赖资源模块的 product_interface
     load_pipeline_service()
     load_sdlc_adapter()
     load_app_audit()