fix: resolve download failures and duplicate messages, add fast playlist detection

- Remove --audio-multi-streams flag (not supported by Alpine yt-dlp 2026.03.17)
- Reuse the fetching message as the format selection message to avoid duplicate text
- Add DetectPlaylist method for fast flat playlist detection before expensive GetMediaInfo
- This avoids stalls on YouTube Music radio URLs with large playlists

internal/dl/ytdlp.go

@@ -194,6 +194,24 @@ func (c *Client) GetPlaylistInfo(url string) (*domain.MediaInfo, error) {
 		return cached, nil
 	}
 
+	isPlaylist, mi, err := c.DetectPlaylist(url)
+	if err != nil {
+		return nil, err
+	}
+	if !isPlaylist {
+		mi.IsPlaylist = false
+		mi.PlaylistCount = 0
+		mi.PlaylistEntries = nil
+	}
+
+	c.setCache(url, mi)
+	return mi, nil
+}
+
+// DetectPlaylist runs a fast flat yt-dlp check to determine if the URL is a playlist.
+// It returns basic info without format details. For non-playlist URLs it returns false.
+// Does NOT cache the result so a subsequent GetMediaInfo call fetches full format info.
+func (c *Client) DetectPlaylist(url string) (bool, *domain.MediaInfo, error) {
 	args := []string{
 		"-J", "--flat-playlist", "--no-download",
 		"--no-warnings",
@@ -206,29 +224,29 @@ func (c *Client) GetPlaylistInfo(url string) (*domain.MediaInfo, error) {
 		args = append(args, "--proxy", c.proxyURL)
 	}
 
-	slog.Info("fetching playlist info", "url", url)
+	slog.Info("detecting playlist", "url", url)
 	out, err := c.run(args)
 	if err != nil {
-		return nil, fmt.Errorf("yt-dlp playlist info failed: %w", err)
+		return false, nil, fmt.Errorf("yt-dlp playlist detection failed: %w", err)
 	}
 
-	var info ytdlpInfo
-	if err := json.Unmarshal(out, &info); err != nil {
-		return nil, fmt.Errorf("parse yt-dlp playlist output: %w", err)
+	var rawInfo ytdlpInfo
+	if err := json.Unmarshal(out, &rawInfo); err != nil {
+		return false, nil, fmt.Errorf("parse yt-dlp output: %w", err)
 	}
 
 	mi := &domain.MediaInfo{
 		URL:             url,
-		Title:           info.Title,
-		Uploader:        info.Uploader,
-		Thumbnail:       info.Thumbnail,
-		IsPlaylist:      true,
-		PlaylistCount:   info.PlaylistCount,
-		PlaylistEntries: c.parsePlaylistEntries(info.Entries),
+		Title:           rawInfo.Title,
+		Uploader:        rawInfo.Uploader,
+		Thumbnail:       rawInfo.Thumbnail,
+		Duration:        rawInfo.Duration,
+		IsPlaylist:      rawInfo.Playlist != "",
+		PlaylistCount:   rawInfo.PlaylistCount,
+		PlaylistEntries: c.parsePlaylistEntries(rawInfo.Entries),
 	}
 
-	c.setCache(url, mi)
-	return mi, nil
+	return mi.IsPlaylist, mi, nil
 }
 
 func (c *Client) parsePlaylistEntries(entries []json.RawMessage) []domain.PlaylistEntry {
@@ -319,7 +337,6 @@ func (c *Client) StartDownload(job *domain.DownloadJob, downloadDir string) (<-c
 	// Language selection if specified
 	if job.Language != "" {
 		args = append(args, "--sub-langs", job.Language)
-		args = append(args, "--audio-multi-streams")
 	}
 
 	// Cookies