refactor(api): 优化字段处理逻辑，默认隐藏所有字段

在FieldsHandler中移除获取隐藏字段的逻辑，默认将所有字段设置为隐藏，交由前端控制显示/隐藏。此更改简化了字段映射逻辑，提高了代码可读性。

server/internal/api/fields.go

@@ -15,8 +15,6 @@ func FieldsHandler(marketing, ymt *sql.DB) http.Handler {
 			db = ymt
 		}
 
-		hiddenDefaults := getHiddenFieldsFromCode(ds)
-
 		var tables []string
 		if ds == "ymt" {
 			tables = []string{"order_info", "order_cash", "order_voucher", "order_digit", "goods_voucher_batch", "goods_voucher_subject_config", "merchant", "activity"}
@@ -37,12 +35,11 @@ func FieldsHandler(marketing, ymt *sql.DB) http.Handler {
 				if label == "" {
 					label = fCanonical
 				}
-				hidden := isFieldHidden(hiddenDefaults, tCanonical, fCanonical)
 				fields = append(fields, map[string]interface{}{
 					"key":    tCanonical + "." + fCanonical,
 					"field":  fCanonical,
 					"label":  label,
-					"hidden": hidden,
+					"hidden": true, // 默认全部隐藏，交由前端控制显示/隐藏
 				})
 			}
 			tDisplay := displayTable(ds, tbl)