pub fn note_begin(stage: &str)Expand description
Open a named progress stage, logging (stage....
Perl Common/Error.pm:ProgressSpinup L435ff. Pair every call with
note_end, which closes the parenthesis — the nesting of those
parentheses is what makes a conversion log readable as a phase tree.
Perl also stamps a NOTE_TIMERS entry here so the close can report elapsed
time; this port logs the structure without the timing (per-phase wall times
are the telemetry module’s job).