swarm: orchestrator, CCR context compilation, containment rules, primitive seam

- swarm.el: coordinator running fan-out/converge on El NATIVE threads
  (thread.el spawn/join) in bounded concurrency waves, order-preserving;
  convergence strategies collect/merge/vote/reduce; integer per-mille failure
  threshold (El float division is unreliable — avoided deliberately).
- ccr.el: per-worker Compiled Context Routing — retrieval/scoping/compaction
  into a bounded, minimal package; the compiled-context boundary is the
  security boundary (a worker cannot receive or leak sibling inputs).
- containment.el: the three Swarm containment rules enforced via scope tokens
  (Rule 1 no join, Rule 2 no open, Rule 3 no lateral edge) + execution-tree
  lateral-edge check.
- primitives.el: attend/think/intend/act/learn seam the swarm composes over,
  with engram-backed fallbacks and an explicit binding point for the reshape.
- prototype json_array_push in el_runtime.h (defined but unprototyped).

test_swarm: 12/12 — native fan-out/converge, bounded concurrency, durable
tracking, CCR bounding + non-leak, and all three containment rules.

lang/el-compiler/runtime/el_runtime.h

@@ -275,6 +275,7 @@ el_val_t  json_array_get_string(el_val_t json_str, el_val_t index);
 el_val_t  json_escape_string(el_val_t sv);
 el_val_t  json_build_object(el_val_t kvs);
 el_val_t  json_build_array(el_val_t items);
+el_val_t  json_array_push(el_val_t arr_v, el_val_t elem_v);  /* defined in el_runtime.c */
 
 /* ── Time ────────────────────────────────────────────────────────────────── */