pub fn trace(labels: &Labels, message: &str)Expand description
Emit a LogLevel::Trace event carrying the component’s
labels through the [crate::trace_router]. Returns
immediately when no --trace=<spec> was configured (the
router is empty), so the hot-path cost of an unused trace
site is one atomic load + branch.
Trace events DO NOT flow to session.log — they are routed
to dedicated trace files configured by --trace= so the
main session log stays usable as a Debug-and-up record.