fix: progress always at 0% and context cancelled before sendDocument

- Fix progress template: remove spurious stderr: prefix and switch to
  _percent_str/_speed_str/_eta_str keys (progress.percent outputs NA
  for HLS streams with unknown total size)
- Update progress regex to match new template format:
  DLPROG| 45.2%|   1.05MiB/s|00:45
- Fix context cancellation bug: clearActiveJob was cancelling dlCtx
  before handleDownloadCompletion could send the document
- Update progress test cases to match new template output format

internal/handler/download.go

@@ -400,11 +400,11 @@ func (h *Handler) runDownload(ctx context.Context, job *domain.DownloadJob) {
 
 	h.trackDownloadProgress(ctx, job, updates)
 
-	h.clearActiveJob(job.UserID)
-
 	if job.Status == domain.StatusCompleted {
 		h.handleDownloadCompletion(ctx, job)
 	}
+
+	h.clearActiveJob(job.UserID)
 }
 
 // trackDownloadProgress reads progress updates from yt-dlp and updates the Telegram message.