fix(canvas): 视频设置 - 按渠道能力隐藏尺寸并联动分辨率宽高

backend/internal/service/model_capability.go

@@ -532,8 +532,12 @@ func validateVideoCapabilityConfig(value *VideoCapabilityConfig) error {
 	if err := validateVideoDuration(value.Duration); err != nil {
 		return err
 	}
-	if len(value.Ratios) == 0 || strings.TrimSpace(value.DefaultRatio) == "" || !containsCapabilityString(value.Ratios, value.DefaultRatio) {
-		return BadAuthRequest("请至少配置一个画面比例，并选择默认比例")
+	if len(value.Ratios) == 0 {
+		if strings.TrimSpace(value.DefaultRatio) != "" {
+			return BadAuthRequest("未配置画面比例时不能设置默认比例")
+		}
+	} else if strings.TrimSpace(value.DefaultRatio) == "" || !containsCapabilityString(value.Ratios, value.DefaultRatio) {
+		return BadAuthRequest("默认画面比例必须属于支持值")
 	}
 	if len(value.Resolutions) == 0 {
 		if strings.TrimSpace(value.DefaultResolution) != "" {