OptionalidentifierOptional caller-supplied identifier. When non-empty, the note is upserted
on (traceId, name='note', identifier) — repeated calls with the same
identifier overwrite the existing note. When omitted, the server stamps a
unique px-trace-note:<uuid> identifier so each call appends a new note.
The note text to add to the trace.
The OpenTelemetry trace ID (hex format without 0x prefix).
Parameters for a single trace note.