fix(lotus): report an ended screenshare even when LiveKit unpublishes first (#39)

LiveKit's own ended handler runs before ours and unpublishes the share;
a listener removed during that dispatch never fires. Decide from the
track's readyState on LocalTrackUnpublished as well. Verified end to end:
closing the shared source now toasts in the host.

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

src/lotus/lotusScreenshareWatch.ts

@@ -45,6 +45,7 @@ export function startLotusScreenshareWatch(
 
   const attach = (room: LivekitRoom): void => {
     let cleanupTrack: (() => void) | undefined;
+    let endedHook: (() => void) | undefined;
 
     const watchPublication = (pub: LocalTrackPublication): void => {
       if (pub.source !== Track.Source.ScreenShare) return;
@@ -55,7 +56,12 @@ export function startLotusScreenshareWatch(
       let sentNoFrames = false;
       let sentAlone = false;
 
-      const onEnded = (): void => notify("ended");
+      let sentEnded = false;
+      const onEnded = (): void => {
+        if (sentEnded) return;
+        sentEnded = true;
+        notify("ended");
+      };
       const onMute = (): void => {
         if (sentNoFrames) return;
         noFramesTimer = setTimeout(() => {
@@ -67,6 +73,7 @@ export function startLotusScreenshareWatch(
         if (noFramesTimer !== undefined) clearTimeout(noFramesTimer);
         noFramesTimer = undefined;
       };
+      endedHook = onEnded;
       mst?.addEventListener("ended", onEnded);
       mst?.addEventListener("mute", onMute);
       mst?.addEventListener("unmute", onUnmute);
@@ -86,11 +93,17 @@ export function startLotusScreenshareWatch(
         if (noFramesTimer !== undefined) clearTimeout(noFramesTimer);
         clearInterval(aloneTimer);
         cleanupTrack = undefined;
+        endedHook = undefined;
       };
     };
 
+    // LiveKit's own `ended` handler runs first and unpublishes the share; a
+    // listener removed during that dispatch never fires, so decide from the
+    // track's state here as well.
     const onUnpublished = (pub: LocalTrackPublication): void => {
-      if (pub.source === Track.Source.ScreenShare) cleanupTrack?.();
+      if (pub.source !== Track.Source.ScreenShare) return;
+      if (pub.track?.mediaStreamTrack?.readyState === "ended") endedHook?.();
+      cleanupTrack?.();
     };
 
     room.on(RoomEvent.LocalTrackPublished, watchPublication);