feat(billing): enhance task billing process with video input detection and updated pricing logic

- Added `EstimateBilling` function to check for video input in request metadata and return corresponding discount ratios.
- Updated `ModelPriceHelperPerCall` to incorporate new pricing logic based on model ratios and video input.
- Enhanced task billing logs to include model ratio information and adjusted calculations for actual quota based on additional multipliers.
- Introduced `renderTaskBillingProcess` to improve rendering of task billing information in the UI.

relay/channel/task/doubao/adaptor.go

@@ -132,6 +132,49 @@ func (a *TaskAdaptor) BuildRequestHeader(_ *gin.Context, req *http.Request, _ *r
 	return nil
 }
 
+// EstimateBilling 检测请求 metadata 中是否包含视频输入，返回视频折扣 OtherRatio。
+func (a *TaskAdaptor) EstimateBilling(c *gin.Context, info *relaycommon.RelayInfo) map[string]float64 {
+	req, err := relaycommon.GetTaskRequest(c)
+	if err != nil {
+		return nil
+	}
+	if hasVideoInMetadata(req.Metadata) {
+		if ratio, ok := GetVideoInputRatio(info.OriginModelName); ok {
+			return map[string]float64{"video_input": ratio}
+		}
+	}
+	return nil
+}
+
+// hasVideoInMetadata 直接检查 metadata 的 content 数组是否包含 video_url 条目，
+// 避免构建完整的上游 requestPayload。
+func hasVideoInMetadata(metadata map[string]interface{}) bool {
+	if metadata == nil {
+		return false
+	}
+	contentRaw, ok := metadata["content"]
+	if !ok {
+		return false
+	}
+	contentSlice, ok := contentRaw.([]interface{})
+	if !ok {
+		return false
+	}
+	for _, item := range contentSlice {
+		itemMap, ok := item.(map[string]interface{})
+		if !ok {
+			continue
+		}
+		if itemMap["type"] == "video_url" {
+			return true
+		}
+		if _, has := itemMap["video_url"]; has {
+			return true
+		}
+	}
+	return false
+}
+
 // BuildRequestBody converts request into Doubao specific format.
 func (a *TaskAdaptor) BuildRequestBody(c *gin.Context, info *relaycommon.RelayInfo) (io.Reader, error) {
 	req, err := relaycommon.GetTaskRequest(c)

relay/channel/task/doubao/constants.go

@@ -10,3 +10,16 @@ var ModelList = []string{
 }
 
 var ChannelName = "doubao-video"
+
+// videoInputRatioMap 视频输入折扣比率（含视频单价 / 不含视频单价）。
+// 管理员应将 ModelRatio 设置为"不含视频"的较高费率，
+// 系统在检测到视频输入时自动乘以此折扣。
+var videoInputRatioMap = map[string]float64{
+	"doubao-seedance-2-0-260128":      28.0 / 46.0, // ~0.6087
+	"doubao-seedance-2-0-fast-260128": 22.0 / 37.0, // ~0.5946
+}
+
+func GetVideoInputRatio(modelName string) (float64, bool) {
+	r, ok := videoInputRatioMap[modelName]
+	return r, ok
+}