fix: show first progress update immediately instead of waiting for 5%

- Always show the first nonzero progress update so users don't see 0% for
  extended periods on slow downloads or fragment-based downloads
- Keep 5% throttle for subsequent updates to avoid excessive API calls
- Add readProgress summary logging (lines, matches, stderr length)
- Fix progressKeyboard not being updated until progress >= 5%

internal/dl/progress.go

@@ -3,6 +3,7 @@ package dl
 import (
 	"bufio"
 	"io"
+	"log/slog"
 	"regexp"
 	"strconv"
 	"strings"
@@ -60,8 +61,11 @@ func parseProgressLine(line string) *progressUpdate {
 func readProgress(stderr io.ReadCloser, updates chan<- *domain.DownloadJob, job *domain.DownloadJob) {
 	var stderrBuf strings.Builder
 	scanner := bufio.NewScanner(stderr)
+	lineCount := 0
+	matchCount := 0
 	for scanner.Scan() {
 		line := scanner.Text()
+		lineCount++
 
 		if stderrBuf.Len() < 4096 {
 			stderrBuf.WriteString(line)
@@ -72,10 +76,12 @@ func readProgress(stderr io.ReadCloser, updates chan<- *domain.DownloadJob, job
 		if parsed == nil {
 			continue
 		}
+		matchCount++
 		job.Progress = parsed.pct
 		job.Speed = parsed.speed
 		job.ETA = parsed.eta
 		updates <- job
 	}
 	job.StderrLog = stderrBuf.String()
+	slog.Info("readProgress finished", "url", job.URL, "lines", lineCount, "matches", matchCount, "stderr_len", len(job.StderrLog))
 }

internal/handler/download.go

@@ -396,6 +396,8 @@ func (h *Handler) runDownload(ctx context.Context, job *domain.DownloadJob) {
 
 	lastProgress := 0.0
 	for upd := range updates {
+		slog.Info("progress update", "pct", upd.Progress, "speed", upd.Speed, "status", upd.Status)
+
 		h.mu.Lock()
 		currentJob := h.activeJobs[job.UserID]
 		h.mu.Unlock()
@@ -419,8 +421,14 @@ func (h *Handler) runDownload(ctx context.Context, job *domain.DownloadJob) {
 			return
 		}
 
-		if upd.Progress-lastProgress >= domain.ProgressThreshold || upd.Status == domain.StatusCompleted {
+		// Always show the first real progress update, then throttle at 5% intervals
+		if upd.Progress > 0 && lastProgress == 0 {
 			lastProgress = upd.Progress
+		} else if upd.Progress-lastProgress < domain.ProgressThreshold && upd.Status != domain.StatusCompleted {
+			continue
+		} else {
+			lastProgress = upd.Progress
+		}
 
 		if upd.Progress > domain.QuotaProgressThreshold && !job.QuotaApplied && job.FileSize > 0 {
 			job.QuotaApplied = true
@@ -431,7 +439,6 @@ func (h *Handler) runDownload(ctx context.Context, job *domain.DownloadJob) {
 		text := fmt.Sprintf("Downloading: %s", job.Title)
 		h.editText(ctx, job.ChatID, job.MessageID, text, &kb)
 	}
-	}
 
 	h.mu.Lock()
 	delete(h.activeJobs, job.UserID)