fn saga_id_of(cmd: &Command) -> Option<u64>Expand description
Pull the saga_id off a Command if its variant carries one.
Used by send_frame’s pending-buffer machinery: when a buffered
command is dropped (overflow or 30s host-disconnect timeout),
emit_drop_failure emits Event::SagaFailed { saga_id } so the
saga’s bracket closes cleanly instead of waiting forever.
CPD-1 added saga_id fields on host-bound variants; CPD-3 made
send_command live from the saga coordinator, so the drop
machinery is now saga-correctness-relevant.