fix: validate prices must be >= 0, remove debug logs

backend/internal/handler/admin/channel_handler.go

@@ -226,14 +226,34 @@ func pricingRequestToService(reqs []channelModelPricingRequest) []service.Channe
 	return result
 }
 
-// validatePricingBillingMode 校验按次/图片计费模式必须配置 PerRequestPrice 或 Intervals
+// validatePricingBillingMode 校验计费配置
 func validatePricingBillingMode(pricing []service.ChannelModelPricing) error {
 	for _, p := range pricing {
+		// 按次/图片模式必须配置默认价格或区间
 		if p.BillingMode == service.BillingModePerRequest || p.BillingMode == service.BillingModeImage {
 			if p.PerRequestPrice == nil && len(p.Intervals) == 0 {
 				return errors.New("per-request price or intervals required for per_request/image billing mode")
 			}
 		}
+		// 校验价格不能为负
+		if err := validatePriceNotNegative("input_price", p.InputPrice); err != nil {
+			return err
+		}
+		if err := validatePriceNotNegative("output_price", p.OutputPrice); err != nil {
+			return err
+		}
+		if err := validatePriceNotNegative("cache_write_price", p.CacheWritePrice); err != nil {
+			return err
+		}
+		if err := validatePriceNotNegative("cache_read_price", p.CacheReadPrice); err != nil {
+			return err
+		}
+		if err := validatePriceNotNegative("image_output_price", p.ImageOutputPrice); err != nil {
+			return err
+		}
+		if err := validatePriceNotNegative("per_request_price", p.PerRequestPrice); err != nil {
+			return err
+		}
 		// 校验 interval：至少有一个价格字段非空
 		for _, iv := range p.Intervals {
 			if iv.InputPrice == nil && iv.OutputPrice == nil &&
@@ -247,6 +267,13 @@ func validatePricingBillingMode(pricing []service.ChannelModelPricing) error {
 	return nil
 }
 
+func validatePriceNotNegative(field string, val *float64) error {
+	if val != nil && *val < 0 {
+		return fmt.Errorf("%s must be >= 0", field)
+	}
+	return nil
+}
+
 func formatMaxTokens(max *int) string {
 	if max == nil {
 		return "∞"