fix: codes指向正确的表名和字段名

- prodtypeid: prodtype→product_category(db=product_management)
- productid: textfield name→product_name(db=product_management)
- 添加dbname支持跨库JOIN

models/discount_detail.json

@@ -77,15 +77,17 @@
         },
         {
             "field": "prodtypeid",
-            "table": "prodtype",
+            "dbname": "product_management",
+            "table": "product_category",
             "valuefield": "id",
             "textfield": "name"
         },
         {
             "field": "productid",
+            "dbname": "product_management",
             "table": "product",
             "valuefield": "id",
-            "textfield": "name"
+            "textfield": "product_name"
         }
     ]
 }