fix(app): abort the old reader on reconnect (fixes doubled keystroke echo)

reconnect() spawned a new reader/writer but left the previous reader task
running. A reconnect triggered while the old connection was still alive (e.g.
a request timing out during a slow daemon start) left TWO live connections;
the daemon broadcast Output to both, so every byte — including input echo —
arrived twice ("ccucurcurl"). The bridge now stores the reader's JoinHandle
and aborts it before establishing the new connection, guaranteeing a single
live reader.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/src-tauri/src/bridge.rs

@@ -29,6 +29,9 @@ pub struct Bridge {
     tx: Mutex<mpsc::Sender<Envelope>>,
     /// Serializes reconnect attempts.
     reconnect_lock: Mutex<()>,
+    /// The current reader task; aborted on reconnect so a stale connection can't
+    /// keep delivering duplicate output (which doubled keystroke echo).
+    reader: Mutex<tokio::task::JoinHandle<()>>,
     /// Pending request id → reply slot.
     pending: Arc<Mutex<HashMap<u64, oneshot::Sender<Envelope>>>>,
     /// surface id → output channel into the webview.
@@ -102,13 +105,13 @@ async fn spawn_connection(
     app: &AppHandle,
     pending: Arc<Mutex<HashMap<u64, oneshot::Sender<Envelope>>>>,
     out_channels: Arc<Mutex<HashMap<String, Channel<Vec<u8>>>>>,
-) -> Result<mpsc::Sender<Envelope>> {
+) -> Result<(mpsc::Sender<Envelope>, tokio::task::JoinHandle<()>)> {
     let stream = ensure_daemon(sock).await?;
     let (read_half, write_half) = stream.into_split();
     let (tx, rx) = mpsc::channel::<Envelope>(256);
     spawn_writer(write_half, rx);
-    spawn_reader(read_half, app.clone(), pending, out_channels);
-    Ok(tx)
+    let reader = spawn_reader(read_half, app.clone(), pending, out_channels);
+    Ok((tx, reader))
 }
 
 impl Bridge {
@@ -116,7 +119,7 @@ impl Bridge {
         let sock = socket_path()?;
         let pending: Arc<Mutex<HashMap<u64, oneshot::Sender<Envelope>>>> = Arc::default();
         let out_channels: Arc<Mutex<HashMap<String, Channel<Vec<u8>>>>> = Arc::default();
-        let tx = spawn_connection(&sock, &app, pending.clone(), out_channels.clone()).await?;
+        let (tx, reader) = spawn_connection(&sock, &app, pending.clone(), out_channels.clone()).await?;
         Ok(Self {
             next_id: AtomicU64::new(1),
             app,
@@ -124,6 +127,7 @@ impl Bridge {
             gen: AtomicU64::new(0),
             tx: Mutex::new(tx),
             reconnect_lock: Mutex::new(()),
+            reader: Mutex::new(reader),
             pending,
             out_channels,
         })
@@ -139,8 +143,12 @@ impl Bridge {
         }
         // Drop in-flight reply slots — their connection is gone; they'll error out.
         self.pending.lock().await.clear();
-        let new_tx = spawn_connection(&self.sock, &self.app, self.pending.clone(), self.out_channels.clone()).await?;
+        // Kill the old reader FIRST so it can't keep delivering output on a stale
+        // connection alongside the new one (the cause of doubled keystroke echo).
+        self.reader.lock().await.abort();
+        let (new_tx, new_reader) = spawn_connection(&self.sock, &self.app, self.pending.clone(), self.out_channels.clone()).await?;
         *self.tx.lock().await = new_tx;
+        *self.reader.lock().await = new_reader;
         self.gen.fetch_add(1, Ordering::Release);
         let _ = self.app.emit("spacesh:reconnected", ());
         Ok(())
@@ -205,7 +213,7 @@ fn spawn_reader(
     app: AppHandle,
     pending: Arc<Mutex<HashMap<u64, oneshot::Sender<Envelope>>>>,
     out_channels: Arc<Mutex<HashMap<String, Channel<Vec<u8>>>>>,
-) {
+) -> tokio::task::JoinHandle<()> {
     tokio::spawn(async move {
         loop {
             match read_frame(&mut read_half).await {
@@ -232,7 +240,7 @@ fn spawn_reader(
                 }
             }
         }
-    });
+    })
 }
 
 // ---- Tauri commands ----