feat(lotus): report speakingWhileMuted for the local participant in io.lotus.call_state (#37)

While the mic is muted LiveKit keeps the capture alive and merely disables the
published MediaStreamTrack, so VAD says nothing. lotusMutedSpeech taps a CLONE
of the published track (post-denoise when the in-source processor is active),
samples RMS at 10 Hz through an AnalyserNode and runs a hysteresis gate (300 ms
of voice on, 800 ms of quiet off, threshold ≈ −36 dBFS). The tap only exists
while a muted mic publication exists; the flag is set on the local entry of
io.lotus.call_state only and is never sent to other participants. Gate is
unit-tested; verified end-to-end: muted with a tone mic → true within 2.5 s,
silence → false, unmute → false.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/lotus/lotusCallState.test.ts

@@ -53,7 +53,11 @@ function mockMember(id: string, userId: string): Member {
 }
 
 function mockVm(members: Member[]): CallViewModel {
-  return { userMedia$: of(members) } as unknown as CallViewModel;
+  return {
+    userMedia$: of(members),
+    // no livekit connections → the muted-speech tap never starts
+    allConnections$: of({ getConnections: () => [] }),
+  } as unknown as CallViewModel;
 }
 
 function participantsOf(call: number): unknown[] {