feat: support /v1/responses API

relay/common/relay_info.go

@@ -200,6 +200,10 @@ func GenRelayInfo(c *gin.Context) *RelayInfo {
 	if streamSupportedChannels[info.ChannelType] {
 		info.SupportStreamOptions = true
 	}
+	// responses 模式不支持 StreamOptions
+	if relayconstant.RelayModeResponses == info.RelayMode {
+		info.SupportStreamOptions = false
+	}
 	return info
 }