self-review 2026-08-01: emit discrete wm_saturation_transition ISE

wm_saturated was a sampled boolean — the 0->1 onset and 1->0 release
moments were only recoverable by hand-diffing consecutive heartbeats.
Emit a low-rate transition ISE at each edge carrying the WM top-5 at
that instant, so the composition that caused the regime change is
captured rather than the composition up to 59s later. First beat of a
boot never fires (restart is not a transition).

awareness.el

@@ -212,6 +212,21 @@ fn emit_heartbeat() -> Void {
     // cap-pinned regime; wm_top0_streak counts consecutive heartbeats with
     // the same node in WM slot 0 (state-tracked, same mechanism as wm_delta).
     let wm_sat: Int = if wmc >= 24 { 1 } else { 0 }
+    // Saturation TRANSITION event (2026-08-01 self-review): wm_saturated is a
+    // sampled boolean — the 0→1 onset and 1→0 release moments were only
+    // recoverable by diffing consecutive heartbeats by hand. Emit a discrete
+    // low-rate ISE at each edge, carrying the WM top-5 at that instant so the
+    // composition that CAUSED the regime change is captured, not the
+    // composition 59 seconds later. State-tracked like wm_delta; first beat
+    // of a boot never fires (prev defaults to current) — a restart is not a
+    // transition.
+    let prev_sat_raw: String = state_get("soul.prev_wm_saturated")
+    let prev_sat: Int = if str_eq(prev_sat_raw, "") { wm_sat } else { str_to_int(prev_sat_raw) }
+    if wm_sat != prev_sat {
+        let sat_dir: String = if wm_sat == 1 { "onset" } else { "release" }
+        ise_post("{\"event\":\"wm_saturation_transition\",\"direction\":\"" + sat_dir + "\",\"wm_active\":" + int_to_str(wmc) + ",\"wm_top\":" + wm_top + ",\"ts\":" + int_to_str(ts) + "}")
+    }
+    state_set("soul.prev_wm_saturated", int_to_str(wm_sat))
     let wm_top0: String = json_array_get(wm_top, 0)
     let wm_top0_id: String = json_get(wm_top0, "id")
     let prev_top0: String = state_get("soul.prev_wm_top0")