fix: normalize DEFAULT quality to prevent Tidal/Qobuz API failures

go_backend/qobuz.go

@@ -2259,7 +2259,7 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		qobuzQuality = "6"
 	case "HI_RES":
 		qobuzQuality = "7"
-	case "HI_RES_LOSSLESS":
+	case "HI_RES_LOSSLESS", "", "DEFAULT":
 		qobuzQuality = "27"
 	}
 	GoLog("[Qobuz] Using quality: %s (mapped from %s)\n", qobuzQuality, req.Quality)

go_backend/tidal.go

@@ -2212,7 +2212,7 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 	}
 
 	quality := req.Quality
-	if quality == "" {
+	if quality == "" || quality == "DEFAULT" {
 		quality = "LOSSLESS"
 	}