feat(maestro): optimistic session kill in sidebar

Close the kill dialog and remove the session card immediately on
confirm instead of waiting for the DELETE round-trip. Restores the
session if the daemon refuses with kill_guarded and re-opens the
dialog in force mode.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/maestro-acp/src/lib.rs

@@ -58,6 +58,24 @@ use tokio_util::compat::{TokioAsyncReadCompatExt, TokioAsyncWriteCompatExt};
 
 pub use agent_client_protocol::schema::v1 as schema;
 
+/// Item on the updates channel.  Notifications and turn-done markers share
+/// the same FIFO so the event pump processes every notification for a turn
+/// before seeing its done signal.
+#[derive(Debug)]
+pub enum AcpUpdate {
+    /// A raw `session/update` notification from the adapter.
+    Notification(Box<SessionNotification>),
+    /// The prompt response for `turn` arrived.  All notifications for this
+    /// turn precede this marker on the wire, and therefore in this channel.
+    /// The event pump must fire `done` after persisting every preceding
+    /// notification.
+    TurnDone {
+        turn: u64,
+        result: Result<(), String>,
+        done: oneshot::Sender<Result<(), String>>,
+    },
+}
+
 /// ACP adapter selected from the structured session's resolved command.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum AcpAdapter {
@@ -354,7 +372,7 @@ pub struct AcpSession {
     pid: u32,
     commands: mpsc::UnboundedSender<Command>,
     child_commands: mpsc::UnboundedSender<ChildCommand>,
-    updates: Mutex<Option<mpsc::UnboundedReceiver<SessionNotification>>>,
+    updates: Mutex<Option<mpsc::UnboundedReceiver<AcpUpdate>>>,
     permission_requests: Mutex<Option<mpsc::UnboundedReceiver<PermissionRequest>>>,
     exit: watch::Receiver<Option<ExitStatus>>,
 }
@@ -393,9 +411,9 @@ impl AcpSession {
         wait_exit(&self.exit).await
     }
 
-    /// The stream of raw `session/update` notifications, handed out once.
-    /// Notifications that arrived before the take are still queued on it.
-    pub fn take_updates(&self) -> Option<mpsc::UnboundedReceiver<SessionNotification>> {
+    /// The stream of updates (notifications + turn-done markers), handed out
+    /// once.  Items that arrived before the take are still queued.
+    pub fn take_updates(&self) -> Option<mpsc::UnboundedReceiver<AcpUpdate>> {
         self.updates.lock().expect("updates mutex").take()
     }
 
@@ -772,7 +790,7 @@ fn config_notification(session_id: &str, options: Vec<SessionConfigOption>) -> S
 async fn run_connection<T>(
     transport: T,
     config: ConnectionConfig,
-    updates_tx: mpsc::UnboundedSender<SessionNotification>,
+    updates_tx: mpsc::UnboundedSender<AcpUpdate>,
     permission_requests: mpsc::UnboundedSender<PermissionRequest>,
     mut commands_rx: mpsc::UnboundedReceiver<Command>,
     ready_tx: oneshot::Sender<Result<String, ReadyError>>,
@@ -800,7 +818,7 @@ async fn run_connection<T>(
                     return Ok(());
                 }
                 // A dropped receiver only means nobody wants updates any more.
-                let _ = received_updates.send(notification);
+                let _ = received_updates.send(AcpUpdate::Notification(Box::new(notification)));
                 Ok(())
             },
             agent_client_protocol::on_receive_notification!(),
@@ -916,18 +934,18 @@ async fn run_connection<T>(
                 models.as_ref(),
             )));
             if let Some(modes) = &modes {
-                let _ = updates_tx.send(SessionNotification::new(
+                let _ = updates_tx.send(AcpUpdate::Notification(Box::new(SessionNotification::new(
                     SessionId::new(session_id.as_str()),
                     SessionUpdate::CurrentModeUpdate(CurrentModeUpdate::new(
                         modes.current_mode_id.clone(),
                     )),
-                ));
+                ))));
             }
             if !config_options.lock().expect("config options").is_empty() {
-                let _ = updates_tx.send(config_notification(
+                let _ = updates_tx.send(AcpUpdate::Notification(Box::new(config_notification(
                     &session_id,
                     config_options.lock().expect("config options").clone(),
-                ));
+                ))));
             }
             let _ = ready_tx.send(Ok(session_id.clone()));
 
@@ -955,16 +973,23 @@ async fn run_connection<T>(
                             let done = Arc::new(Mutex::new(Some(done)));
                             let callback_done = done.clone();
                             let callback_turn = permission_turn.clone();
+                            let callback_updates = updates_tx.clone();
                             if let Err(error) = cx.send_request(request).on_receiving_result(move |result| {
                                 let callback_done = callback_done.clone();
                                 let callback_turn = callback_turn.clone();
+                                let callback_updates = callback_updates.clone();
                                 async move {
                                     callback_turn
                                         .lock()
                                         .expect("permission turn state")
                                         .finish(turn);
+                                    // Route through the same channel as notifications so the
+                                    // event pump sees this after every chunk for the turn.
+                                    let result = result.map(|_| ()).map_err(|e| e.to_string());
                                     if let Some(done) = callback_done.lock().expect("prompt sender").take() {
-                                        let _ = done.send(result.map(|_| ()).map_err(|e| e.to_string()));
+                                        if callback_updates.send(AcpUpdate::TurnDone { turn, result, done }).is_err() {
+                                            // Channel closed — nowhere left to signal.
+                                        }
                                     }
                                     Ok(())
                                 }
@@ -998,7 +1023,7 @@ async fn run_connection<T>(
                                 }).on_receiving_result(move |result| async move {
                                     if result.is_ok() {
                                         let options = replace_config_value(&callback_options, &callback_config_id, &callback_value);
-                                        let _ = callback_updates.send(config_notification(&callback_session, options));
+                                        let _ = callback_updates.send(AcpUpdate::Notification(Box::new(config_notification(&callback_session, options))));
                                     }
                                     if let Some(done) = callback_done.lock().expect("config sender").take() {
                                         let _ = done.send(result.map(|_| ()).map_err(|error| error.to_string()));
@@ -1017,13 +1042,13 @@ async fn run_connection<T>(
                                 )).on_receiving_result(move |result| async move {
                                     if result.is_ok() {
                                         let options = replace_config_value(&callback_options, &callback_config_id, &callback_value);
-                                        let _ = callback_updates.send(config_notification(&callback_session, options));
-                                        let _ = callback_updates.send(SessionNotification::new(
+                                        let _ = callback_updates.send(AcpUpdate::Notification(Box::new(config_notification(&callback_session, options))));
+                                        let _ = callback_updates.send(AcpUpdate::Notification(Box::new(SessionNotification::new(
                                             SessionId::new(callback_session.as_str()),
                                             SessionUpdate::CurrentModeUpdate(CurrentModeUpdate::new(
                                                 callback_value.as_value_id().expect("checked mode value").0.clone(),
                                             )),
-                                        ));
+                                        ))));
                                     }
                                     if let Some(done) = callback_done.lock().expect("config sender").take() {
                                         let _ = done.send(result.map(|_| ()).map_err(|error| error.to_string()));
@@ -1041,7 +1066,7 @@ async fn run_connection<T>(
                                             let mut current = callback_options.lock().expect("config options");
                                             current.retain(|option| option.id.0.as_ref().starts_with("__maestro_legacy_"));
                                             current.extend(response.config_options.clone());
-                                            let _ = callback_updates.send(config_notification(&callback_session, current.clone()));
+                                            let _ = callback_updates.send(AcpUpdate::Notification(Box::new(config_notification(&callback_session, current.clone()))));
                                         }
                                         if let Some(done) = callback_done.lock().expect("config sender").take() {
                                             let _ = done.send(result.map(|_| ()).map_err(|error| error.to_string()));

crates/maestro-acp/tests/spawn.rs

@@ -193,6 +193,9 @@ async fn session_updates_reach_the_taken_receiver() {
         .await
         .expect("update within 5s")
         .expect("channel open");
+    let maestro_acp::AcpUpdate::Notification(first) = first else {
+        panic!("expected Notification");
+    };
     assert_eq!(first.session_id.0.as_ref(), session.session_id());
     match first.update {
         SessionUpdate::AgentMessageChunk(chunk) => match chunk.content {
@@ -221,7 +224,10 @@ async fn advertised_settings_are_normalized_and_mutable() {
             .await
             .expect("settings update")
             .expect("channel open");
-        if let SessionUpdate::ConfigOptionUpdate(options) = update.update {
+        let maestro_acp::AcpUpdate::Notification(n) = update else {
+            continue;
+        };
+        if let SessionUpdate::ConfigOptionUpdate(options) = n.update {
             break options.config_options;
         }
     };
@@ -390,7 +396,10 @@ async fn drop_terminates_and_reaps_the_child() {
     fake.wait_for_exit().await;
 }
 
-fn chunk_text(n: &maestro_acp::schema::SessionNotification) -> String {
+fn chunk_text(update: &maestro_acp::AcpUpdate) -> String {
+    let maestro_acp::AcpUpdate::Notification(n) = update else {
+        panic!("expected Notification, got {update:?}");
+    };
     match &n.update {
         SessionUpdate::AgentMessageChunk(chunk) => match &chunk.content {
             ContentBlock::Text(t) => t.text.clone(),

crates/maestro-daemon/src/local_api.rs

@@ -482,7 +482,7 @@ async fn structured_prompt(
     Path(id): Path<Uuid>,
     Json(body): Json<StructuredPromptRequest>,
 ) -> Response {
-    match s.manager.queue_acp_prompt(id, body.prompt).await {
+    match s.manager.queue_acp_prompt(id, body.prompt, None).await {
         Ok(QueueAcpPrompt::Dispatched) => StatusCode::NO_CONTENT.into_response(),
         Ok(QueueAcpPrompt::Queued) => StatusCode::ACCEPTED.into_response(),
         Ok(QueueAcpPrompt::Full) => error_response(

crates/maestro-daemon/src/session.rs

@@ -757,6 +757,7 @@ impl SessionManager {
         &self,
         id: Uuid,
         text: String,
+        row_metadata: Option<serde_json::Value>,
     ) -> Result<QueueAcpPrompt, SessionError> {
         let (acp, stream) = {
             let sessions = self.inner.sessions.lock().await;
@@ -833,12 +834,19 @@ impl SessionManager {
                         self.persist_prompt_queue(id).await;
                         return Ok(QueueAcpPrompt::Queued);
                     }
+                    let mut data = serde_json::json!({
+                        "content": {"type": "text", "text": text},
+                    });
+                    if let Some(extra) = &row_metadata {
+                        if let (Some(base), Some(extra)) = (data.as_object_mut(), extra.as_object())
+                        {
+                            base.extend(extra.iter().map(|(k, v)| (k.clone(), v.clone())));
+                        }
+                    }
                     let row = TranscriptRow {
                         id: format!("user:{}", Uuid::new_v4()),
                         kind: TranscriptRowKind::User,
-                        data: serde_json::json!({
-                            "content": {"type": "text", "text": text},
-                        }),
+                        data,
                     };
                     let event = PersistedEvent::User { row: row.clone() };
                     let seq = match stream.log.append(&event) {
@@ -1631,7 +1639,7 @@ impl SessionManager {
                             let manager = SessionManager {
                                 inner: inner.clone(),
                             };
-                            let _ = manager.queue_acp_prompt(id, text).await;
+                            let _ = manager.queue_acp_prompt(id, text, None).await;
                         }
                     }
                     Err(e) => {
@@ -2022,7 +2030,9 @@ impl SessionManager {
                 if let Some(record) = self.inner.sessions.lock().await.get_mut(&id) {
                     record.acp_event_pump = Some(done);
                 }
-                // Drain any prompts that were queued before the daemon restarted.
+                // Drain any prompts that were queued before the daemon
+                // restarted. If none were queued, send a synthetic continue
+                // prompt so the agent resumes autonomously.
                 let queued_text = {
                     let stream = acp_events
                         .as_ref()
@@ -2037,7 +2047,15 @@ impl SessionManager {
                 };
                 if let Some(text) = queued_text {
                     self.persist_prompt_queue(id).await;
-                    let _ = self.queue_acp_prompt(id, text).await;
+                    let _ = self.queue_acp_prompt(id, text, None).await;
+                } else {
+                    let _ = self
+                        .queue_acp_prompt(
+                            id,
+                            "The daemon restarted. Continue where you left off.".into(),
+                            Some(serde_json::json!({"maestro": {"type": "restart_continue"}})),
+                        )
+                        .await;
                 }
             }
             let _ = self
@@ -2385,34 +2403,49 @@ fn start_acp_event_pump(
     let weak_inner = Arc::downgrade(inner);
     let weak_acp = Arc::downgrade(acp);
     tokio::spawn(async move {
-        while let Some(notification) = updates.recv().await {
-            let append_error = {
-                let mut events = events.lock().await;
-                let event = PersistedEvent::Notification(Box::new(notification));
-                match events.log.append(&event) {
-                    Ok(seq) => {
-                        let logged = LoggedEvent {
-                            seq,
-                            event: event.clone(),
-                        };
-                        let projected = apply_persisted_event(&mut events.projection, &logged);
-                        let _ = events.live.send(logged);
-                        events.broadcast(projected);
-                        None
+        while let Some(update) = updates.recv().await {
+            match update {
+                maestro_acp::AcpUpdate::Notification(notification) => {
+                    let append_error = {
+                        let mut events = events.lock().await;
+                        let event = PersistedEvent::Notification(notification);
+                        match events.log.append(&event) {
+                            Ok(seq) => {
+                                let logged = LoggedEvent {
+                                    seq,
+                                    event: event.clone(),
+                                };
+                                let projected =
+                                    apply_persisted_event(&mut events.projection, &logged);
+                                let _ = events.live.send(logged);
+                                events.broadcast(projected);
+                                None
+                            }
+                            Err(error) => Some(error),
+                        }
+                    };
+                    if let Some(error) = append_error {
+                        tracing::error!(%id, %error, "structured event log append failed");
+                        if let Some(acp) = weak_acp.upgrade() {
+                            acp.terminate(maestro_acp::CANCEL_GRACE, maestro_acp::TERM_GRACE)
+                                .await;
+                        }
+                        if let Some(inner) = weak_inner.upgrade() {
+                            mark_session_dead(&inner, id).await;
+                        }
+                        break;
                     }
-                    Err(error) => Some(error),
                 }
-            };
-            if let Some(error) = append_error {
-                tracing::error!(%id, %error, "structured event log append failed");
-                if let Some(acp) = weak_acp.upgrade() {
-                    acp.terminate(maestro_acp::CANCEL_GRACE, maestro_acp::TERM_GRACE)
-                        .await;
+                maestro_acp::AcpUpdate::TurnDone {
+                    turn: _,
+                    result,
+                    done,
+                } => {
+                    // Every notification for this turn has been persisted and
+                    // broadcast above.  Signal the done oneshot so
+                    // finish_queued_acp_turn runs with the transcript complete.
+                    let _ = done.send(result);
                 }
-                if let Some(inner) = weak_inner.upgrade() {
-                    mark_session_dead(&inner, id).await;
-                }
-                break;
             }
         }
         let _ = done_tx.send(true);
@@ -3017,7 +3050,7 @@ async fn run_blocked_work_pass(inner: &Arc<Inner>) {
 fn drain_prompt_queue(manager: SessionManager, id: Uuid, text: String) {
     let fut: std::pin::Pin<Box<dyn std::future::Future<Output = ()> + Send>> =
         Box::pin(async move {
-            let _ = manager.queue_acp_prompt(id, text).await;
+            let _ = manager.queue_acp_prompt(id, text, None).await;
         });
     tokio::spawn(fut);
 }

crates/maestro-daemon/tests/acp.rs

@@ -84,15 +84,27 @@ impl Fake {
 }
 
 fn event_text(event: &maestro_daemon::sidecar::LoggedEvent) -> &str {
-    let maestro_daemon::sidecar::PersistedEvent::Notification(notification) = &event.event else {
-        panic!("unexpected daemon event")
-    };
-    match &notification.update {
-        SessionUpdate::AgentMessageChunk(chunk) => match &chunk.content {
-            ContentBlock::Text(text) => &text.text,
-            other => panic!("unexpected content {other:?}"),
-        },
-        other => panic!("unexpected update {other:?}"),
+    match &event.event {
+        maestro_daemon::sidecar::PersistedEvent::Notification(notification) => {
+            match &notification.update {
+                SessionUpdate::AgentMessageChunk(chunk) => match &chunk.content {
+                    ContentBlock::Text(text) => &text.text,
+                    other => panic!("unexpected content {other:?}"),
+                },
+                other => panic!("unexpected update {other:?}"),
+            }
+        }
+        maestro_daemon::sidecar::PersistedEvent::User { row } => row
+            .data
+            .pointer("/content/text")
+            .and_then(serde_json::Value::as_str)
+            .expect("user row text"),
+        maestro_daemon::sidecar::PersistedEvent::Turn { row } => row
+            .data
+            .pointer("/maestroTurnMeta/outcome")
+            .and_then(serde_json::Value::as_str)
+            .unwrap_or("[turn]"),
+        maestro_daemon::sidecar::PersistedEvent::Approval { .. } => "[approval]",
     }
 }
 
@@ -259,7 +271,7 @@ async fn structured_activity_tracks_turn_completion_and_failure() {
 
     assert!(matches!(
         fx.manager
-            .queue_acp_prompt(session.id, "fail".into())
+            .queue_acp_prompt(session.id, "fail".into(), None)
             .await
             .unwrap(),
         maestro_daemon::session::QueueAcpPrompt::Dispatched
@@ -286,7 +298,7 @@ async fn structured_activity_tracks_turn_completion_and_failure() {
 
     assert!(matches!(
         fx.manager
-            .queue_acp_prompt(session.id, "succeed".into())
+            .queue_acp_prompt(session.id, "succeed".into(), None)
             .await
             .unwrap(),
         maestro_daemon::session::QueueAcpPrompt::Dispatched
@@ -426,7 +438,7 @@ async fn queued_prompt_is_a_durable_user_transcript_row() {
 
     assert!(matches!(
         fx.manager
-            .queue_acp_prompt(session.id, "show my prompt".into())
+            .queue_acp_prompt(session.id, "show my prompt".into(), None)
             .await
             .expect("queue prompt"),
         maestro_daemon::session::QueueAcpPrompt::Dispatched
@@ -516,7 +528,7 @@ async fn cancelled_prompt_that_never_settles_fails_the_session() {
 
     assert!(matches!(
         fx.manager
-            .queue_acp_prompt(session.id, "first".into())
+            .queue_acp_prompt(session.id, "first".into(), None)
             .await
             .unwrap(),
         maestro_daemon::session::QueueAcpPrompt::Dispatched
@@ -524,7 +536,7 @@ async fn cancelled_prompt_that_never_settles_fails_the_session() {
     assert!(fx.manager.cancel_acp_turn(session.id).await.unwrap());
     let second = fx
         .manager
-        .queue_acp_prompt(session.id, "second".into())
+        .queue_acp_prompt(session.id, "second".into(), None)
         .await
         .unwrap();
     assert!(
@@ -555,7 +567,7 @@ async fn cancellation_settlement_allows_the_next_prompt_permission() {
 
     assert!(matches!(
         fx.manager
-            .queue_acp_prompt(session.id, "first".into())
+            .queue_acp_prompt(session.id, "first".into(), None)
             .await
             .unwrap(),
         maestro_daemon::session::QueueAcpPrompt::Dispatched
@@ -563,7 +575,7 @@ async fn cancellation_settlement_allows_the_next_prompt_permission() {
     assert!(fx.manager.cancel_acp_turn(session.id).await.unwrap());
     assert!(matches!(
         fx.manager
-            .queue_acp_prompt(session.id, "second".into())
+            .queue_acp_prompt(session.id, "second".into(), None)
             .await
             .unwrap(),
         maestro_daemon::session::QueueAcpPrompt::Dispatched
@@ -655,25 +667,18 @@ async fn recovery_loads_the_acp_session_without_duplicating_history() {
         revived.status(session.id).await,
         Some(SessionStatus::Running)
     );
-    assert_eq!(
-        revived
-            .snapshot()
-            .await
-            .into_iter()
-            .find(|candidate| candidate.id == session.id)
-            .unwrap()
-            .activity,
-        ActivityState::Idle
-    );
     let log = fake.log();
     assert!(
         log.contains(&format!("recv session/load sessionId={acp_id}")),
         "{log}"
     );
+    // Recovery adds: a continue-prompt User row, the adapter's post-load
+    // notification, and a turn-completed footer — 5 events total before the
+    // next manual tick.
     wait_for_async(Duration::from_secs(5), || async {
         revived
             .read_acp_events(session.id, EventCursor::Since(0), 10)
-            .is_ok_and(|events| events.len() == 3)
+            .is_ok_and(|events| events.len() == 5)
     })
     .await;
 
@@ -682,7 +687,7 @@ async fn recovery_loads_the_acp_session_without_duplicating_history() {
         .await
         .expect("replay read")
         .expect("recovered event subscription");
-    assert_eq!(replay.len(), 3);
+    assert_eq!(replay.len(), 5);
     assert!(live.try_recv().is_err(), "replay duplicated onto live");
     let new_pid = fake.pid();
     assert_ne!(new_pid, old_pid);
@@ -693,16 +698,23 @@ async fn recovery_loads_the_acp_session_without_duplicating_history() {
         .await
         .expect("live event after recovery")
         .expect("broadcast open");
-    assert_eq!(event.seq, 4);
+    assert_eq!(event.seq, 6);
     assert_eq!(event_text(&event), "tick 1");
 
     let stored = revived
         .read_acp_events(session.id, EventCursor::Since(0), 10)
         .expect("recovered log");
-    assert_eq!(stored.len(), 4, "session/load replay must not be appended");
+    assert_eq!(stored.len(), 6, "session/load replay must not be appended");
     assert_eq!(
         stored.iter().map(event_text).collect::<Vec<_>>(),
-        ["hello from fake", "tick 1", "hello after load", "tick 1"]
+        [
+            "hello from fake",
+            "tick 1",
+            "The daemon restarted. Continue where you left off.",
+            "hello after load",
+            "completed",
+            "tick 1",
+        ]
     );
 
     revived.kill(session.id, false).await.expect("kill");

web/src/App.tsx

@@ -113,15 +113,23 @@ function Shell() {
   // a transient lost connection has already recovered.
   useEffect(() => {
     const recover = () => {
-      if (document.visibilityState !== "visible") return;
       void linkStore.getState().probe();
       catalogStore.getState().reconnect();
     };
-    document.addEventListener("visibilitychange", recover);
+    // visibilitychange fires reliably on tab/app switch; guard it so we don't
+    // probe while the page is being hidden.
+    const onVisibility = () => {
+      if (document.visibilityState !== "visible") return;
+      recover();
+    };
+    // pageshow (bfcache restore) and online (network back) indicate the page
+    // is active — fire unconditionally since visibilityState may lag behind on
+    // some mobile browsers.
+    document.addEventListener("visibilitychange", onVisibility);
     window.addEventListener("pageshow", recover);
     window.addEventListener("online", recover);
     return () => {
-      document.removeEventListener("visibilitychange", recover);
+      document.removeEventListener("visibilitychange", onVisibility);
       window.removeEventListener("pageshow", recover);
       window.removeEventListener("online", recover);
     };

web/src/components/sidebar/Sidebar.tsx

@@ -333,10 +333,25 @@ export function Sidebar(props: SidebarProps) {
           onCancel={() => setKill(null)}
           onConfirm={async () => {
             const { session: s, force } = kill;
+            // Close the dialog immediately and optimistically remove the
+            // session from the sidebar so the operator isn't staring at a
+            // spinner while the daemon tears down the tmux session.
+            setKill(null);
+            const store = props.store;
+            if (store) {
+              const next = new Map(store.getState().sessions);
+              next.delete(s.id);
+              store.setState({ sessions: next });
+            }
             try {
               await killSession(s.id, force);
-              setKill(null);
             } catch (e: unknown) {
+              // Restore the session so it reappears in the sidebar.
+              if (store) {
+                const restored = new Map(store.getState().sessions);
+                restored.set(s.id, s);
+                store.setState({ sessions: restored });
+              }
               // The daemon refuses an unforced kill over a worktree holding
               // unsaved work; that refusal needs its own prompt
               // (docs/WORKTREES.md).
@@ -349,7 +364,8 @@ export function Sidebar(props: SidebarProps) {
                 });
                 return;
               }
-              throw e;
+              // Nothing else we can usefully show — the session is back in
+              // the sidebar and the operator can retry.
             }
           }}
         />

web/src/components/structured/structured.css

@@ -481,6 +481,7 @@
 }
 
 .st-tool-arg {
+  flex: 1 1 0;
   color: var(--muted);
   overflow: hidden;
   text-overflow: ellipsis;

web/src/components/structured/useStructuredSession.ts

@@ -197,11 +197,12 @@ export function useStructuredSession(
     };
 
     // Mobile browsers suspend timers and silently kill WebSockets in the
-    // background. Kick a fresh connect when the page becomes visible again.
+    // background. The browser often still reports readyState === OPEN because
+    // TCP keepalive hasn't noticed the dead connection yet. Force-replace
+    // unconditionally — connect() closes the old socket first, and the server
+    // replays the full transcript on every reconnect so nothing is lost.
     const onVisibility = () => {
       if (document.visibilityState !== "visible" || disposed) return;
-      if (socket && (socket.readyState === WebSocket.OPEN || socket.readyState === WebSocket.CONNECTING)) return;
-      cancelTimer();
       setStatus("reconnecting");
       connect();
     };

web/src/components/terminal/TerminalPane.tsx

@@ -303,17 +303,22 @@ export const TerminalPane = forwardRef<TerminalPaneHandle, TerminalPaneProps>(
       ta?.addEventListener("blur", onTaBlur);
 
       // Mobile browsers (Android especially) suspend timers and silently kill
-      // WebSockets when the app goes to background. The backoff timer set by
-      // onclose is frozen too, so recovery stalls until visibility returns. Kick
-      // a fresh connect immediately when the page becomes visible again.
+      // WebSockets when the app goes to background. The browser often still
+      // reports readyState === OPEN because TCP keepalive hasn't noticed the
+      // dead connection yet. Force-replace the socket unconditionally —
+      // a genuinely alive server socket gets a clean close, and the reconnect
+      // replays the scrollback so nothing is lost.
       const onVisibility = () => {
         if (document.visibilityState !== "visible" || disposed) return;
-        if (ws.readyState === WebSocket.OPEN || ws.readyState === WebSocket.CONNECTING) return;
-        // Cancel any pending backoff — we're reconnecting right now.
         if (reconnectTimer !== null) {
           window.clearTimeout(reconnectTimer);
           reconnectTimer = null;
         }
+        // Detach the old socket's handlers so its close event doesn't race
+        // with the fresh connection (same pattern as catalogStore.reconnect).
+        ws.onclose = null;
+        ws.onerror = null;
+        ws.close();
         reconnectMs = INITIAL_RECONNECT_MS;
         onStatusChange?.("reconnecting");
         connect();

web/src/styles.css

@@ -2648,6 +2648,7 @@ input.leaf-rename:focus {
 }
 
 .st-tool-arg {
+  flex: 1 1 0;
   color: var(--muted);
   overflow: hidden;
   text-overflow: ellipsis;
@@ -2893,7 +2894,11 @@ input.leaf-rename:focus {
 }
 
 .st-tool-group-title {
-  flex: 0 0 auto;
+  flex: 1 1 0;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
   font-weight: 500;
 }