swarm: document real-cognition binding + HAVE_CURL build note in README

lang/swarm/README.md

@@ -113,6 +113,27 @@ already routes every worker primitive call through this one switch, and the same
 harness runs the bound path. Today `SWARM_PRIMITIVE_SEAM=decorated` still runs
 green because the binding falls back to the stub — proving the flip path executes.
 
+## Real cognition — the seam is BOUND
+
+`primitive_binding.el` is bound to the api-reshape agent's proven primitives
+(`wt/api-reshape@d4f401d`): `bound_think -> op_think` (GET `/api/think`), real
+768-dim gradients over the engram geometry. `reshape_surface.el` composes those
+read/cognition primitives verbatim (`op_think/read/attend/learn`).
+
+`tests/harness_real_cognition.el` runs the **local swarm on real cognition**,
+17/17 green with `SWARM_PRIMITIVE_SEAM=decorated` against the `:8901` clone: 8
+native-thread workers, each a real `think` over its CCR-scoped **node-id anchor**
+(free-text anchors return "geometry unavailable"), `@manager` reduce+vote, all
+three containment rules, afferent telemetry, durable tracking. Per-anchor support
+counts (e.g. 6 / 16 / 87) drive a genuine, cognition-derived vote.
+
+> **Build note (load-bearing):** the swarm build **must** define `HAVE_CURL`
+> (`build.sh` does). Without it every `http_*` builtin is a
+> `{"error":"not built with HAVE_CURL"}` stub — real HTTP silently disappears.
+
+Writes (`attend`/`learn`, `POST`) are gated behind `SWARM_WRITE_HEALTHY=1` and the
+api-reshape agent's gate-1 write-healthy clone; the proven run is read-cognition.
+
 ## Built vs stubbed (honest)
 
 **Real, tested:**