Expand description
Cocoon outputChannel.append notification. Twin of output.append;
see OutputCreate.rs for the duplicate-wire rationale.
Tries the per-channel coalescer first; falls back to legacy
per-append emit when OutputCoalesce=0 is set or when the payload
has no value field. Channel-aware dev_log tagging routes Git/SCM
to grpc, everything else to output-verbose.