fix(pulseaudio): suppress disconnect error during Stream::drop teardown

The play_all driver thread surfaces ClientError::Disconnected when the
reactor drops the source's eof_tx — which happens not only on real
server disconnect but also as a *direct consequence* of Stream::drop
queueing DeletePlaybackStream and the server processing it. The error
callback then fires "PulseAudio client disconnected" on every clean
teardown, despite the connection being healthy.

Check the cancel flag in the play_all spawn before emit_error,
mirroring the latency thread's existing pre-poll cancel check. After a
clean Stream::drop the cancel flag is already set when play_all
unblocks, so the spurious notification is silenced; real disconnects
(reactor exits, socket closed) leave the flag clear and still surface
through the user's error_callback.

Author: knz

CHANGELOG.md

@@ -145,6 +145,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **JACK**: Poisoned error callback mutex no longer silently drops subsequent error notifications.
 - **PulseAudio**: Poisoned locks now exit the thread gracefully instead of panicking.
 - **PulseAudio**: Fix server-side stream leak when a `Stream` is dropped.
+- **PulseAudio**: Remove spurious "PulseAudio client disconnected" warnings during stream cleanup.
 - **JACK**: Port registration failure now fails stream creation instead of silently failing.
 - **JACK**: `activate_async()` failure now returns an error instead of panicking.
 - **JACK**: Sample rate is now validated against the live JACK server at stream creation time.

src/host/pulseaudio/stream.rs

@@ -239,9 +239,15 @@ impl Stream {
         // when the stream is stopped by the user.
         let stream_clone = stream.clone();
         let error_callback_clone = error_callback.clone();
+        let cancel_driver = handle.cancel.clone();
         let driver_handle = std::thread::spawn(move || {
             if let Err(e) = block_on(stream_clone.play_all()) {
-                emit_error(&error_callback_clone, Error::from(e));
+                // A server playback error is expected when the client
+                // closes their stream. No need to report it back to
+                // the client.
+                if !cancel_driver.load(atomic::Ordering::Relaxed) {
+                    emit_error(&error_callback_clone, Error::from(e));
+                }
             }
         });