feat: 移除“租户管理员为用户充值 / 每租户一套余额”能力：余额统一为全局用户余额

backend/pkg/consts/consts.go

@@ -398,7 +398,7 @@ func ContentAccessStatusItems() []requests.KV {
 // orders
 
 // swagger:enum OrderType
-// ENUM( content_purchase, topup )
+// ENUM( content_purchase )
 type OrderType string
 
 // Description returns the Chinese label for the specific enum value.
@@ -406,8 +406,6 @@ func (t OrderType) Description() string {
 	switch t {
 	case OrderTypeContentPurchase:
 		return "购买内容"
-	case OrderTypeTopup:
-		return "充值"
 	default:
 		return "未知类型"
 	}
@@ -460,14 +458,12 @@ func OrderStatusItems() []requests.KV {
 // tenant_ledgers
 
 // swagger:enum TenantLedgerType
-// ENUM( credit_topup, debit_purchase, credit_refund, freeze, unfreeze, adjustment )
+// ENUM( debit_purchase, credit_refund, freeze, unfreeze, adjustment )
 type TenantLedgerType string
 
 // Description returns the Chinese label for the specific enum value.
 func (t TenantLedgerType) Description() string {
 	switch t {
-	case TenantLedgerTypeCreditTopup:
-		return "充值入账"
 	case TenantLedgerTypeDebitPurchase:
 		return "购买扣款"
 	case TenantLedgerTypeCreditRefund: