fix(monitor): clamp Span.Progress Count to Total

common/monitor/progress.go

@@ -158,6 +158,14 @@ func (s *Span) Progress() Progress {
 		}
 		parentCount += childTotal * child.Count / child.Total
 	}
+	// Clamp parentCount to parentTotal. The "zero-total child is complete"
+	// fallback above can otherwise push parentCount beyond parentTotal when
+	// the parent has already consumed its own count and a running child is
+	// reporting no work units, which would surface as >100% progress in the
+	// dashboard.
+	if parentCount > parentTotal {
+		parentCount = parentTotal
+	}
 	return Progress{
 		Name:       s.name,
 		Status:     s.status,

common/monitor/progress_overflow_test.go

@@ -0,0 +1,25 @@
+package monitor
+
+import (
+	"context"
+	"testing"
+)
+
+// TestProgress_ZeroTotalChildDoesNotExceed100Percent pins the behavior of the
+// zero-total child fallback in Span.Progress. Before the clamp, a parent
+// with total=2,count=2 plus a running child with total=0 would return
+// Count=3,Total=2 (150%), which confused the dashboard progress bar.
+//
+// The clamp ensures Count <= Total for every case the fallback handles.
+func TestProgress_ZeroTotalChildDoesNotExceed100Percent(t *testing.T) {
+	_, parent := Start(context.Background(), "parent", 2)
+	parent.Add(2) // parent's own work is complete
+
+	ctx := context.WithValue(context.Background(), spanKeyName, parent)
+	_, _ = Start(ctx, "child", 0)
+
+	got := parent.Progress()
+	if got.Count > got.Total {
+		t.Fatalf("Progress.Count (%d) exceeds Progress.Total (%d)", got.Count, got.Total)
+	}
+}