feat(Sora): 完成Sora网关接入与媒体能力

新增 Sora 网关路由、账号调度与同步服务\n补充媒体代理与签名 URL、模型列表动态拉取\n完善计费配置、前端支持与相关测试

backend/internal/service/billing_service.go

@@ -303,6 +303,14 @@ type ImagePriceConfig struct {
 	Price4K *float64 // 4K 尺寸价格（nil 表示使用默认值）
 }
 
+// SoraPriceConfig Sora 按次计费配置
+type SoraPriceConfig struct {
+	ImagePrice360          *float64
+	ImagePrice540          *float64
+	VideoPricePerRequest   *float64
+	VideoPricePerRequestHD *float64
+}
+
 // CalculateImageCost 计算图片生成费用
 // model: 请求的模型名称（用于获取 LiteLLM 默认价格）
 // imageSize: 图片尺寸 "1K", "2K", "4K"
@@ -332,6 +340,65 @@ func (s *BillingService) CalculateImageCost(model string, imageSize string, imag
 	}
 }
 
+// CalculateSoraImageCost 计算 Sora 图片按次费用
+func (s *BillingService) CalculateSoraImageCost(imageSize string, imageCount int, groupConfig *SoraPriceConfig, rateMultiplier float64) *CostBreakdown {
+	if imageCount <= 0 {
+		return &CostBreakdown{}
+	}
+
+	unitPrice := 0.0
+	if groupConfig != nil {
+		switch imageSize {
+		case "540":
+			if groupConfig.ImagePrice540 != nil {
+				unitPrice = *groupConfig.ImagePrice540
+			}
+		default:
+			if groupConfig.ImagePrice360 != nil {
+				unitPrice = *groupConfig.ImagePrice360
+			}
+		}
+	}
+
+	totalCost := unitPrice * float64(imageCount)
+	if rateMultiplier <= 0 {
+		rateMultiplier = 1.0
+	}
+	actualCost := totalCost * rateMultiplier
+
+	return &CostBreakdown{
+		TotalCost:  totalCost,
+		ActualCost: actualCost,
+	}
+}
+
+// CalculateSoraVideoCost 计算 Sora 视频按次费用
+func (s *BillingService) CalculateSoraVideoCost(model string, groupConfig *SoraPriceConfig, rateMultiplier float64) *CostBreakdown {
+	unitPrice := 0.0
+	if groupConfig != nil {
+		modelLower := strings.ToLower(model)
+		if strings.Contains(modelLower, "sora2pro-hd") {
+			if groupConfig.VideoPricePerRequestHD != nil {
+				unitPrice = *groupConfig.VideoPricePerRequestHD
+			}
+		}
+		if unitPrice <= 0 && groupConfig.VideoPricePerRequest != nil {
+			unitPrice = *groupConfig.VideoPricePerRequest
+		}
+	}
+
+	totalCost := unitPrice
+	if rateMultiplier <= 0 {
+		rateMultiplier = 1.0
+	}
+	actualCost := totalCost * rateMultiplier
+
+	return &CostBreakdown{
+		TotalCost:  totalCost,
+		ActualCost: actualCost,
+	}
+}
+
 // getImageUnitPrice 获取图片单价
 func (s *BillingService) getImageUnitPrice(model string, imageSize string, groupConfig *ImagePriceConfig) float64 {
 	// 优先使用分组配置的价格