pub fn set_log_file(path: &Path) -> Result<()>Expand description
Direct the log sink to a file. Opens for append-writes,
installs the crate::log_sink async writer thread.
Producers thereafter try_send and never block — see SRD-02
§“Display and Diagnostic Decoupling”. Silently no-ops on a
second call — the first session wins (one run per process).