refactor: remove fallback audio collection in case empty after namespace fix

adapter/volcano/request.go

@@ -51,7 +51,7 @@ func buildRequest(opts Options) ([]byte, error) {
 
 	body := requestBody{
 		User:      ttsUser{UID: opts.UID},
-		Namespace: "BidirectionalTTS",
+		Namespace: "UnidirectionalTTS",
 		ReqParams: ttsReqParams{
 			Text:    opts.Text,
 			Speaker: opts.Speaker,

adapter/volcano/response.go

@@ -105,11 +105,7 @@ func ParseStream(body io.Reader, started time.Time) (*ParsedStream, error) {
 				gotFirstChunk = true
 			}
 		case "":
-			// 无 event 字段的元数据行(上游 TTSSentenceStart 偶发省略 event),
-			// debug 模式打印便于排查;正常情况静默跳过。
-			if common.DebugLog && resp.Code == 0 {
-				log.Printf("volcano: 无 event 字段 code=%d sequence=%d sentence=%s data_len=%d", resp.Code, resp.Sequence, resp.SentenceText(), len(resp.Data))
-			}
+			// 传输帧,跳过
 		default:
 			if common.DebugLog {
 				log.Printf("volcano: 忽略未识别事件 event=%q sequence=%d sentence=%s data_len=%d", resp.Event, resp.Sequence, resp.SentenceText(), len(resp.Data))