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>
