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_test.go

@@ -67,6 +67,27 @@ func TestParseProgressLine(t *testing.T) {
 			eta:    "00:02",
 			hasRes: true,
 		},
+		{
+			line:   "[download] 100.0% of ~   1.00KiB at    976.20B/s ETA Unknown (frag 0/18)",
+			pct:    100.0,
+			speed:  "976.20B/s",
+			eta:    "",
+			hasRes: true,
+		},
+		{
+			line:   "[download]  16.7% of ~  18.00KiB at    976.20B/s ETA Unknown (frag 0/18)",
+			pct:    16.7,
+			speed:  "976.20B/s",
+			eta:    "",
+			hasRes: true,
+		},
+		{
+			line:   "[download]  11.1% of ~   8.34MiB at  716.47KiB/s ETA 00:08 (frag 1/18)",
+			pct:    11.1,
+			speed:  "716.47KiB/s",
+			eta:    "00:08",
+			hasRes: true,
+		},
 		{
 			line:   "[download]  1.2% of unknown size at 0.00B/s ETA Unknown",
 			hasRes: false,
@@ -196,6 +217,9 @@ func TestParseProgressLineEdgeCases(t *testing.T) {
 		{"[download]   0.0% of 1.00GiB at    0.00B/s ETA 00:00", "multiple spaces", true},
 		{"[download] 100.0% of 1.00GiB at 999.99MiB/s ETA 00:00", "high speed", true},
 		{"[download] 100.0% of 999.99TiB at 1.00TiB/s ETA 00:00", "large numbers", true},
+		{"[download] 100.0% of ~   1.00KiB at    976.20B/s ETA Unknown (frag 0/18)", "hls frag first", true},
+		{"[download]  16.7% of ~  18.00KiB at    976.20B/s ETA Unknown (frag 0/18)", "hls frag", true},
+		{"[download]  11.1% of ~   8.34MiB at  716.47KiB/s ETA 00:08 (frag 1/18)", "hls frag with eta", true},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {