lotus(#7): audio/screenshare quality controls via widget action

Adds io.lotus.set_quality (toWidget): caps mic audio bitrate and
screenshare bitrate/framerate via RTCRtpSender.setParameters (no
republish). Settings are sticky and re-applied on LocalTrackPublished so
they survive mute/unmute and reconnects. These encoding controls lived in
EC's module scope, unreachable from the host against the prebuilt bundle.
Additive: no-op unless the host sends the action.

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

src/lotus/lotusActions.ts

@@ -23,10 +23,13 @@ export enum LotusWidgetActions {
   FocusParticipant = "io.lotus.focus_participant",
   /** toWidget: mix an audio clip into the local published mic track. */
   InjectAudio = "io.lotus.inject_audio",
+  /** toWidget: set audio/screenshare encoding quality (bitrate/framerate). */
+  SetQuality = "io.lotus.set_quality",
 }
 
 /** toWidget Lotus actions that must be allow-listed in `initializeWidget`. */
 export const LOTUS_TO_WIDGET_ACTIONS: LotusWidgetActions[] = [
   LotusWidgetActions.FocusParticipant,
   LotusWidgetActions.InjectAudio,
+  LotusWidgetActions.SetQuality,
 ];