self-review 2026-07-30: auto_term stopword filter, real idle_ms, bounded beginSession

- awareness.el: curiosity auto_term was the raw first word of a WM
  label with no term-quality scoring — observed seeds included What,
  Colon, Prose, Context. Replaced the 7-word genre blocklist whack-a-
  mole with a delimited stopword membership test (function words +
  document-structure words); topical terms pass untouched. Verified
  live: seeds now ReasonEdit, Reasoning-model, Self-review.
- routes.el + awareness.el: idle counter only reset on rare inbox
  synthesis-requests, so idle==pulse always (zero information).
  handle_request now stamps soul.last_activity_ts on every inbound
  HTTP request; heartbeat emits idle_ms = ms since last request
  (-1 until first request of a boot).
- neuron-api.el: beginSession concatenated a depth-2 spread plus the
  unbounded self-hub neighbor dump — multi-MB response, doubled by
  wrapper re-escaping, socket died on every call. Now depth-1 and
  the hub dump dropped (identity loading has its own tool). Verified:
  beginSession returns instead of closing the socket.

routes.el

@@ -358,6 +358,14 @@ fn handle_connectors(method: String, clean: String, body: String) -> String {
 fn handle_request(method: String, path: String, body: String) -> String {
     let clean: String = strip_query(path)
 
+    // ACTIVITY STAMP (2026-07-30 self-review): every inbound HTTP request —
+    // MCP wrapper calls, chat, API — marks real external activity. Before
+    // this, "idle" was only reset by rare inbox synthesis-requests, so the
+    // heartbeat idle field tracked uptime exactly (idle == pulse on every
+    // beat) and carried zero information. The awareness heartbeat now
+    // reports idle_ms = wall-clock ms since this stamp.
+    state_set("soul.last_activity_ts", int_to_str(time_now()))
+
     // Rate limit check. Extract caller IP from REMOTE_ADDR env var (set by the
     // EL HTTP runtime for each request). Skip enforcement when empty so
     // loopback/internal callers are never blocked.