cli: nil error results in empty error string

cli/telemetry/errors.go

@@ -2,7 +2,9 @@ package telemetry
 
 // Map errors to fixed strings to avoid leaking sensitive data inside error messages.
 func classifyCmdErr(e error) string {
-	_ = e
+	if e == nil {
+		return ""
+	}
 	switch {
 	default:
 		return "unknown error"