Return the W3C Trace Context for this span.
An object with traceId (hex string), spanId (hex string),
and traceFlags (bitmask of trace options).
Trace ID (hex string).
Span ID (hex string).
Trace flags bitmask.
Set a key-value attribute on the span.
Set the span status (OK / ERROR).
Record an exception on this span.
End the span.
Minimal interface for an OpenTelemetry-compatible span. Kinetex does NOT take a hard dependency on @opentelemetry/api.