fix(lotus): Wave-1 audit fixes (EC1–EC6)

- EC1: lotusQuality — track + clearTimeout the 500ms settle re-apply per room
  (was leaking a timer that fired on torn-down rooms).
- EC2/EC3: lotusQuality + lotusAudioInject drive off vm.allConnections$ instead
  of the remote-gated livekitRoomItems$ (were no-ops when alone), matching
  lotusDenoise.
- EC4: lotusDecorations resets its roster to {} on teardown so a decoration from
  a previous call can't render on a shared user in the next one.
- EC5: hoisted a stable useSyncExternalStore subscribe fn (was re-subscribing
  every tile render).
- EC6: lotusFocus only sets the spotlight when the userId field is present
  (a partial payload no longer clears the pin).

tsc clean. Needs a republish to ship.

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

src/lotus/lotusAudioInject.ts

@@ -38,10 +38,13 @@ export function startLotusAudioInject(vm: CallViewModel): () => void {
   const w = widget;
   if (!w) return () => undefined;
 
-  // Track the set of connected LiveKit rooms to publish into.
+  // Track the set of connected LiveKit rooms to publish into. Drive off the
+  // LOCAL participant's connection(s), not `livekitRoomItems$` — that stream
+  // omits rooms with no remote members, so inject would no-op while you're
+  // alone. Map the connections to their livekit rooms like `lotusDenoise.ts`.
   let rooms: LivekitRoom[] = [];
-  const sub = vm.livekitRoomItems$.subscribe((items) => {
-    rooms = items.map((i) => i.livekitRoom);
+  const sub = vm.allConnections$.subscribe((data) => {
+    rooms = data.getConnections().map((c) => c.livekitRoom);
   });
 
   // In-flight clips, so we can abort them on teardown (unmount / vm change /

src/lotus/lotusDecorations.ts

@@ -26,15 +26,16 @@ function emit(): void {
   for (const l of listeners) l();
 }
 
+// Stable module-scope subscribe reference, so `useSyncExternalStore` doesn't
+// re-subscribe (add/remove the listener) on every render of a tile.
+function subscribe(cb: () => void): () => void {
+  listeners.add(cb);
+  return () => listeners.delete(cb);
+}
+
 /** Subscribe a tile avatar to its participant's decoration URL (or undefined). */
 export function useLotusDecoration(userId: string): string | undefined {
-  return useSyncExternalStore(
-    (cb) => {
-      listeners.add(cb);
-      return () => listeners.delete(cb);
-    },
-    () => decorations[userId],
-  );
+  return useSyncExternalStore(subscribe, () => decorations[userId]);
 }
 
 function safeImageUrl(raw: unknown): string | null {
@@ -94,8 +95,12 @@ export function startLotusDecorations(): () => void {
       registrations = 0;
       unregister?.();
       unregister = null;
-      // Intentionally keep the last decorations map: a transient remount must
-      // not drop decorations until the host next pushes an update.
+      // Reset the roster once the last registration goes away, so a decoration
+      // pushed in call A can't leak onto a shared user in call B before the
+      // host re-pushes. Notify listeners so any still-mounted tile drops the
+      // now-stale overlay via the render path.
+      decorations = {};
+      emit();
     }
   };
 }

src/lotus/lotusFocus.ts

@@ -28,8 +28,13 @@ export function startLotusFocus(vm: CallViewModel): () => void {
     // Always reply so the host transport doesn't time out.
     void w.api.transport.reply(ev.detail, {});
     const data = ev.detail.data as { userId?: unknown } | undefined;
-    const userId = typeof data?.userId === "string" ? data.userId : null;
-    vm.setManualSpotlight(userId);
+    // Mirror deafen's partial-payload semantics: a payload that OMITS `userId`
+    // must keep the current spotlight, not clear it. Only act when the key is
+    // actually present — an explicit `null` clears, a string pins that user.
+    if (data && "userId" in data) {
+      const userId = typeof data.userId === "string" ? data.userId : null;
+      vm.setManualSpotlight(userId);
+    }
   };
 
   w.lazyActions.on(LotusWidgetActions.FocusParticipant, handler);

src/lotus/lotusQuality.ts

@@ -48,6 +48,10 @@ export function startLotusQuality(vm: CallViewModel): () => void {
   // Per-room LocalTrackPublished listeners, so sticky settings re-apply on
   // every (re)publish.
   const roomListeners = new Map<LivekitRoom, () => void>();
+  // Per-room settle re-apply timers, so we can cancel a pending 500ms re-apply
+  // when a room is removed or on teardown — otherwise it would fire against a
+  // torn-down room.
+  const settleTimers = new Map<LivekitRoom, ReturnType<typeof setTimeout>>();
   let rooms: LivekitRoom[] = [];
 
   const applyToRoom = (room: LivekitRoom): void => {
@@ -76,8 +80,12 @@ export function startLotusQuality(vm: CallViewModel): () => void {
   const applyToAll = (): void => rooms.forEach(applyToRoom);
 
   // Keep the LocalTrackPublished listeners in sync with the connected rooms.
-  const sub = vm.livekitRoomItems$.subscribe((items) => {
-    const next = items.map((i) => i.livekitRoom);
+  // Drive off the LOCAL participant's connection(s), not `livekitRoomItems$` —
+  // that stream omits rooms with no remote members (returns null for isLocal),
+  // so caps wouldn't apply to the local senders while you're alone. Map the
+  // connections to their livekit rooms exactly like `lotusDenoise.ts` does.
+  const sub = vm.allConnections$.subscribe((data) => {
+    const next = data.getConnections().map((c) => c.livekitRoom);
     rooms = next;
     // Remove listeners for rooms that went away.
     for (const [room, off] of roomListeners) {
@@ -97,7 +105,18 @@ export function startLotusQuality(vm: CallViewModel): () => void {
         // recompute so our cap wins.
         const reapply = (): void => {
           applyToRoom(room);
-          setTimeout(() => applyToRoom(room), 500);
+          // Store the settle timer per room and cancel any pending one, so it
+          // can be cleared on removal/teardown and never fires against a
+          // torn-down room.
+          const prev = settleTimers.get(room);
+          if (prev !== undefined) clearTimeout(prev);
+          settleTimers.set(
+            room,
+            setTimeout(() => {
+              settleTimers.delete(room);
+              applyToRoom(room);
+            }, 500),
+          );
         };
         const events = [
           ParticipantEvent.LocalTrackPublished,
@@ -106,6 +125,9 @@ export function startLotusQuality(vm: CallViewModel): () => void {
         for (const e of events) room.localParticipant.on(e, reapply);
         roomListeners.set(room, () => {
           for (const e of events) room.localParticipant.off(e, reapply);
+          const t = settleTimers.get(room);
+          if (t !== undefined) clearTimeout(t);
+          settleTimers.delete(room);
         });
         applyToRoom(room);
       }