fix: remove --progress-template, parse default [download] output instead

--progress-template output is suppressed in non-TTY subprocesses
(yt-dlp issue #13649). The default [download] progress format
works reliably in pipes. Changes:

- Remove --progress-template from yt-dlp args entirely
- Keep --newline for newline-delimited output in pipe
- Fix progressRE regex to handle HLS format: ~ with leading
  spaces before size (e.g. '~   1.00KiB')
- Fix speed parsing in [download] fallback to handle multiple
  leading spaces (e.g. 'at    976.20B/s')
- Fix ETA parsing to strip (frag n/m) suffix
- Filter Unknown/N/A speed/eta in [download] fallback
- Add test cases for real HLS fragment output format

internal/dl/progress.go

@@ -11,7 +11,7 @@ import (
 	"uptodownBot/internal/domain"
 )
 
-var progressRE = regexp.MustCompile(`\[\w+\]\s+([\d.]+)%\s+of\s+~?([\d.]+)(\w+)`)
+var progressRE = regexp.MustCompile(`\[\w+\]\s+([\d.]+)%\s+of\s+~?\s*([\d.]+)(\w+)`)
 var progressTemplateRE = regexp.MustCompile(`^DLPROG\|\s*([\d.]+)%\|\s*(.*?)\s*\|(.*)$`)
 
 type progressUpdate struct {
@@ -71,15 +71,28 @@ func parseProgressLine(line string) *progressUpdate {
 		rest = rest[idx+1:]
 	}
 	if atIdx := strings.Index(rest, " at "); atIdx >= 0 {
-		afterAt := rest[atIdx+4:]
+		afterAt := strings.TrimSpace(rest[atIdx+4:])
 		if spaceIdx := strings.Index(afterAt, " "); spaceIdx >= 0 {
-			u.speed = strings.TrimSpace(afterAt[:spaceIdx])
+			speedVal := afterAt[:spaceIdx]
+			if !strings.EqualFold(speedVal, "unknown") && speedVal != "N/A" {
+				u.speed = speedVal
+			}
 			rest = afterAt[spaceIdx:]
+		} else {
+			if !strings.EqualFold(afterAt, "unknown") && afterAt != "N/A" {
+				u.speed = afterAt
+			}
+			rest = ""
 		}
 	}
 	if etaIdx := strings.Index(rest, "ETA "); etaIdx >= 0 {
 		etaStr := strings.TrimSpace(rest[etaIdx+4:])
-		u.eta = etaStr
+		if parenPos := strings.Index(etaStr, "("); parenPos > 0 {
+			etaStr = strings.TrimSpace(etaStr[:parenPos])
+		}
+		if !strings.EqualFold(etaStr, "unknown") && etaStr != "N/A" {
+			u.eta = etaStr
+		}
 	}
 
 	return u