fix: progress stuck at 0%, container not respected, audio display, Spotify DRM fallback

- Remove --no-progress from yt-dlp args that suppressed all progress output
- Add --merge-output-format when FormatString is set (container was ignored for combined formats)
- Improve formatLabelForDisplay for audio-only formats missing bitrate (show ID+extension)
- Detect DRM errors (Spotify) and fall back to YouTube Music search via ytsearch1:

internal/dl/ytdlp.go

@@ -220,6 +220,9 @@ func (c *Client) StartDownload(job *domain.DownloadJob, downloadDir string) (<-c
 	// Use explicit format string if set (video+audio combination)
 	if job.FormatString != "" {
 		args = append(args, "-f", job.FormatString)
+		if job.Container != "" {
+			args = append(args, "--merge-output-format", job.Container)
+		}
 	} else {
 		// Build format string for merge
 		switch job.MediaType {
@@ -243,8 +246,8 @@ func (c *Client) StartDownload(job *domain.DownloadJob, downloadDir string) (<-c
 	outputPath := filepath.Join(downloadDir, job.ID+"_%(id)s.%(ext)s")
 	args = append(args, "--output", outputPath)
 
-	// Progress reporting
-	args = append(args, "--newline", "--no-progress")
+	// Progress reporting (--newline for line-based, no --no-progress so we get actual output)
+	args = append(args, "--newline")
 
 	// Language selection if specified
 	if job.Language != "" {
@@ -337,6 +340,40 @@ func CancelDownload(job *domain.DownloadJob) {
 	}
 }
 
+// ytdlpSearchResult holds a single flat search result from yt-dlp.
+type ytdlpSearchResult struct {
+	Title string `json:"title"`
+	URL   string `json:"url"`
+}
+
+// SearchYoutube searches YouTube via yt-dlp ytsearch and returns the first result URL and title.
+func (c *Client) SearchYoutube(query string) (url, title string, err error) {
+	args := []string{
+		"--flat-playlist", "-J", "--no-download",
+		"--no-warnings",
+		"ytsearch1:" + query,
+	}
+	if c.cookiesFile != "" {
+		args = append(args, "--cookies", c.cookiesFile)
+	}
+
+	out, err := c.run(args)
+	if err != nil {
+		return "", "", fmt.Errorf("youtube search failed: %w", err)
+	}
+
+	var info struct {
+		Entries []ytdlpSearchResult `json:"entries"`
+	}
+	if err := json.Unmarshal(out, &info); err != nil {
+		return "", "", fmt.Errorf("parse search result: %w", err)
+	}
+	if len(info.Entries) == 0 {
+		return "", "", fmt.Errorf("no results found")
+	}
+	return info.Entries[0].URL, info.Entries[0].Title, nil
+}
+
 func (c *Client) run(args []string) ([]byte, error) {
 	cmd := exec.Command(c.binaryPath, args...)
 	var stderr bytes.Buffer