fix(model-plaza): apply independent video billing multipliers

backend/internal/handler/model_plaza_handler.go

@@ -92,6 +92,8 @@ type modelPlazaGroup struct {
 	// 不取分组/用户专属倍率。
 	ImageRateIndependent bool    `json:"image_rate_independent"`
 	ImageRateMultiplier  float64 `json:"image_rate_multiplier"`
+	VideoRateIndependent bool    `json:"video_rate_independent"`
+	VideoRateMultiplier  float64 `json:"video_rate_multiplier"`
 	// 分组是否启用长上下文阶梯计费；关闭时模型实付列只展示最低档/基础价。
 	LongContextPricingEnabled bool              `json:"long_context_pricing_enabled"`
 	Models                    []modelPlazaModel `json:"models"`
@@ -211,6 +213,8 @@ func toModelPlazaGroupDTO(g *service.PlazaGroup, userRates map[int64]float64) mo
 		IsExclusive:               g.IsExclusive,
 		ImageRateIndependent:      g.ImageRateIndependent,
 		ImageRateMultiplier:       g.ImageRateMultiplier,
+		VideoRateIndependent:      g.VideoRateIndependent,
+		VideoRateMultiplier:       g.VideoRateMultiplier,
 		LongContextPricingEnabled: g.LongContextPricingEnabled,
 		Models:                    models,
 	}