feat(user): 支持后台调整等级并限制极品专区可见性

backend/internal/modules/order/handler_error.go

@@ -22,6 +22,8 @@ func writeOrderError(c *gin.Context, err error) {
 		response.Error(c, http.StatusConflict, "listing_unavailable", "该账号暂不可租")
 	case errors.Is(err, ErrCannotRentOwnListing):
 		response.BadRequest(c, "不能租用自己发布的账号")
+	case errors.Is(err, ErrPremiumLevelRequired):
+		response.Error(c, http.StatusForbidden, "platinum_level_required", "成长等级达到铂金及以上才能租用极品专区账号")
 	case errors.Is(err, ErrInsufficientBalance):
 		response.Error(c, http.StatusConflict, "insufficient_balance", "钱包余额不足，请先充值")
 	case errors.Is(err, ErrChannelPaymentRequired):

backend/internal/modules/order/lifecycle.go

@@ -103,6 +103,9 @@ func (r *Repository) Create(ctx context.Context, renterID uint64, req CreateRequ
 				DiscountBps: rentergrowth.DefaultDiscountBps,
 			}
 		}
+		if listing.IsPremium && !rentergrowth.CanViewPremiumLevel(growthSnapshot.LevelCode) {
+			return ErrPremiumLevelRequired
+		}
 		rentDiscountAmountCent := rentergrowth.CalculateDiscountCent(pricing.PureCoinAmountCent, pricing.PureCoinPlatformFeeCent, growthSnapshot.DiscountBps)
 		if rentDiscountAmountCent > 0 {
 			pricing.PlatformFeeCent -= rentDiscountAmountCent

backend/internal/modules/order/service.go

@@ -10,6 +10,7 @@ var (
 	ErrInvalidRentHours            = errors.New("invalid rent hours")
 	ErrListingUnavailable          = errors.New("listing unavailable")
 	ErrCannotRentOwnListing        = errors.New("cannot rent own listing")
+	ErrPremiumLevelRequired        = errors.New("platinum level required for premium listing")
 	ErrInsufficientBalance         = errors.New("insufficient balance")
 	ErrOrderCannotPay              = errors.New("order cannot pay")
 	ErrChannelPaymentRequired      = errors.New("channel payment required")