Single-writer append-only JSONL journal keyed by correlation ID: swarm +
worker + convergence records, reconstructable into a status report. Optional
engram mirror via POST /api/node when ENGRAM_URL is set. Coordinator is the
only writer (workers return structured results), which is race-free and
enforces Swarm containment rule 3 by construction.
Also prototype now_millis/now_ns in el_runtime.h (defined in el_runtime.c but
unprototyped — blocked any El program needing a real ms clock under clang 21).
Test proves durability + inspectability end-to-end.
bigmerge