pub fn current_traceparent() -> Option<String>Expand description
W3C traceparent header value extracted from the current
tracing span, formatted as 00-<trace_id>-<span_id>-<flags>.
Returns None when no tracing-opentelemetry layer is installed
(the current span has no associated SpanContext). Used by
outbound HTTP request paths to propagate the trace across a
process boundary — e.g., when a plugin invokes http-get-with-trace
via the host-net WIT import.