lotus(#2): address review — ack contract, rate, param precedence

- Document that io.lotus.call_state is request/response and the host must
  ack it (cinny listenAction replies {}) to avoid 10s-timeout churn (H1).
- Throttle 150ms -> 250ms to reduce widget traffic (M1).
- lotusParam: hash fragment wins over query, matching EC's ParamParser (L1).
- Fix the misleading "opaque" id comment; id is userId:deviceId (L2).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lotus/lotusActions.ts

@@ -11,7 +11,13 @@ Please see LICENSE in the repository root for full details.
  * a circular dependency.
  */
 export enum LotusWidgetActions {
-  /** fromWidget: in-call per-participant speaking / mute state. */
+  /**
+   * fromWidget: in-call per-participant speaking / mute state.
+   * NOTE: matrix-widget-api `transport.send` is request/response — the host
+   * MUST reply/ack each one (cinny's `listenAction` does, replying `{}`),
+   * otherwise every send sits pending for the 10s transport timeout and then
+   * rejects, producing continuous churn + log noise for the whole call.
+   */
   CallState = "io.lotus.call_state",
   /** toWidget: pin/spotlight (or clear, with userId=null) a participant. */
   FocusParticipant = "io.lotus.focus_participant",