Keep agents navigation available after a thread is archived (#53201)

## Why

After a thread was archived externally, the TUI still advertised the Left-arrow agents shortcut, but pressing it in an empty composer did not open the agents view.

## What changed

Reuse the agents navigation handler when connected to an unavailable thread. Preserve the existing empty-composer and editor guards, and require a key press so repeated Left-arrow events do not open the view.

## Testing

Add a regression test for external thread archiving that verifies draft editing, the shortcut hint, ignored key repeats, and opening the agents command center, with a snapshot of the resulting view.

GitOrigin-RevId: a3f36b42bafee948ed7f5842fcb425e414d7e024

codex-rs/tui/src/app/tests/agents_navigation_tests.rs

@@ -49,6 +49,100 @@ async fn agents_navigation_requires_local_daemon() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn externally_archived_thread_keeps_advertised_agents_navigation() -> Result<()> {
+    let (mut app, mut events, _ops) = make_test_app_with_channels().await;
+    let mut tui = crate::tui::test_support::make_test_tui()?;
+    let mut app_server = start_config_write_test_app_server(&app).await?;
+    app.app_server_target = AppServerTarget::LocalDaemon {
+        endpoint: crate::RemoteAppServerEndpoint::UnixSocket {
+            socket_path: AbsolutePathBuf::relative_to_current_dir("codex.sock")?,
+        },
+        allow_embedded_fallback: true,
+    };
+    let init = app.chatwidget_init_for_forked_or_resumed_thread(
+        &mut tui,
+        app.config.clone(),
+        /*initial_user_message*/ None,
+    );
+    app.replace_chat_widget(ChatWidget::new_with_app_event(init));
+    let id = ThreadId::new();
+    app.active_thread_id = Some(id);
+    app.primary_thread_id = Some(id);
+    app.chat_widget
+        .handle_thread_session(test_thread_session(id, app.config.cwd.to_path_buf()));
+    app.ensure_thread_channel(id);
+    app.handle_app_server_event(
+        &app_server,
+        codex_app_server_client::AppServerEvent::ServerNotification(Box::new(
+            ServerNotification::ThreadArchived(ThreadArchivedNotification {
+                thread_id: id.to_string(),
+            }),
+        )),
+    )
+    .await;
+    while events.try_recv().is_ok() {}
+
+    // Left must still edit an existing draft before it can navigate from an empty composer.
+    app.chat_widget
+        .restore_user_message_to_composer("ab".into());
+    app.handle_tui_event(
+        &mut tui,
+        &mut app_server,
+        TuiEvent::Key(KeyCode::Left.into()),
+    )
+    .await?;
+    app.handle_tui_event(
+        &mut tui,
+        &mut app_server,
+        TuiEvent::Key(KeyCode::Char('!').into()),
+    )
+    .await?;
+    assert_eq!(app.chat_widget.composer_text_with_pending(), "a!b");
+    assert!(
+        !std::iter::from_fn(|| events.try_recv().ok())
+            .any(|event| matches!(event, AppEvent::OpenAgentsOverview))
+    );
+    for key in [
+        KeyCode::End.into(),
+        KeyEvent::new(KeyCode::Char('u'), KeyModifiers::CONTROL),
+    ] {
+        app.handle_tui_event(&mut tui, &mut app_server, TuiEvent::Key(key))
+            .await?;
+    }
+    assert!(app.chat_widget.composer_is_empty());
+    assert!(render_bottom_popup(&app.chat_widget, /*width*/ 96).contains("for agents"));
+    app.handle_tui_event(
+        &mut tui,
+        &mut app_server,
+        TuiEvent::Key(KeyEvent::new_with_kind(
+            KeyCode::Left,
+            KeyModifiers::NONE,
+            KeyEventKind::Repeat,
+        )),
+    )
+    .await?;
+    assert!(
+        !std::iter::from_fn(|| events.try_recv().ok())
+            .any(|event| matches!(event, AppEvent::OpenAgentsOverview))
+    );
+    app.handle_tui_event(
+        &mut tui,
+        &mut app_server,
+        TuiEvent::Key(KeyCode::Left.into()),
+    )
+    .await?;
+    let event = events.try_recv()?;
+    assert_matches!(event, AppEvent::OpenAgentsOverview);
+    app.handle_event(&mut tui, &mut app_server, event).await?;
+    insta::assert_snapshot!(
+        "externally_archived_thread_agents",
+        render_bottom_popup(&app.chat_widget, /*width*/ 96)
+    );
+    app_server.shutdown().await?;
+    Ok(())
+}
+
 #[tokio::test]
 async fn pending_windows_sandbox_setup_blocks_thread_replacement() -> Result<()> {
     use crate::app_event::WindowsSandboxEnableMode;

codex-rs/tui/src/app/tests/snapshots/codex_tui__app__tests__agents_navigation_tests__externally_archived_thread_agents.snap

@@ -0,0 +1,28 @@
+---
+source: tui/src/app/tests/agents_navigation_tests.rs
+expression: "render_bottom_popup(&app.chat_widget, 96)"
+---
+  Agent command center  Group: Project  g
+   All 0   Needs you 0   Working 0   Ready 0   Inactive 0                      tab/⇧tab filter
+  ────────────────────────────────────────────────────────────────────────────────────────────
+  Loading tasks…                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+                                                      │
+  ? help  esc back  ↑/↓ move  enter open  n new

codex-rs/tui/src/bottom_pane/chat_composer.rs

@@ -163,6 +163,7 @@
 //! intact until reconnection succeeds, except for the local `/warnings` command.
 //! When connected but the thread is unavailable, configured
 //! submit keys may dispatch explicitly allowed recovery and local commands; other drafts stay put.
+//! Empty-prompt agents navigation remains available with its usual editor and draft guards.
 //! Collapsed pastes expand into editable text so the full draft can be copied before quitting.
 //!
 //! # Reasoning Effort Animations
@@ -3785,9 +3786,7 @@ impl ChatComposer {
             return false;
         }
 
-        if key_hint::plain(KeyCode::Left).is_press(*key_event) && self.agents_navigation_available()
-        {
-            self.app_event_tx.send(AppEvent::OpenAgentsOverview);
+        if self.handle_agents_navigation(*key_event) {
             return true;
         }
 

codex-rs/tui/src/bottom_pane/chat_composer/agents_navigation.rs

@@ -30,4 +30,15 @@ impl ChatComposer {
             && !self.popup_active()
             && !self.draft.textarea.is_vim_operator_pending()
     }
+
+    pub(super) fn handle_agents_navigation(&mut self, key: KeyEvent) -> bool {
+        if key.kind == KeyEventKind::Press
+            && key_hint::plain(KeyCode::Left).is_press(key)
+            && self.agents_navigation_available()
+        {
+            self.app_event_tx.send(AppEvent::OpenAgentsOverview);
+            return true;
+        }
+        false
+    }
 }

codex-rs/tui/src/bottom_pane/chat_composer/reconnect.rs

@@ -1,5 +1,6 @@
 //! Restricted editing retains drafts and allows the local warnings viewer.
 //! Unavailable threads also allow recovery and other local commands.
+//! Connected unavailable threads retain the empty-prompt agents shortcut.
 //! Paste Enter handling is shared with normal submission so buffered newlines survive both paths.
 //! Recovery commands must occupy one line and be visible before the submit key expands pastes.
 //! Offline draft edits also consume the Astra sparkle opportunity before rendering.
@@ -56,6 +57,9 @@ impl ChatComposer {
         key: KeyEvent,
         mode: RestrictedInputMode,
     ) -> InputResult {
+        if mode == RestrictedInputMode::UnavailableThread && self.handle_agents_navigation(key) {
+            return InputResult::None;
+        }
         self.cancel_history_search();
         self.attachments.clear_remote_image_selection();
         self.popups.active = ActivePopup::None;