fix(tui): la bascule TUI native <-> CLI custom ne déclenche plus de faux conflit de visibilité (#189)

crates/application/tests/agent_lifecycle.rs

@@ -1344,6 +1344,68 @@ async fn chat_intent_replaces_existing_pty_instead_of_returning_pty_session() {
     );
 }
 
+#[tokio::test]
+async fn chat_intent_reattaches_existing_structured_session_after_stale_pty_transition() {
+    let profile = profile(
+        pid(9),
+        ContextInjection::convention_file("CLAUDE.md").unwrap(),
+    )
+    .with_structured_adapter(StructuredAdapter::Claude);
+    let (launch, agent, _fs, pty, _bus, sessions, tr, _session) = launch_fixture_with_profile(
+        profile,
+        Some(ContextInjectionPlan::File {
+            target: "CLAUDE.md".to_owned(),
+        }),
+    );
+    let structured = Arc::new(StructuredSessions::new());
+    let factory = FakeStructuredFactory::new(Arc::clone(&tr), sid(888));
+    let launch = launch
+        .with_structured_routing_mode(StructuredRoutingMode::HumanPtyFallback)
+        .with_structured(Arc::new(factory.clone()), Arc::clone(&structured));
+
+    let stale_custom_node = nid(7);
+    structured.insert_in_project(
+        project().id,
+        Arc::new(FakeSession {
+            id: sid(555),
+            conversation_id: Some("engine-session-stale".to_owned()),
+        }),
+        agent.id,
+        stale_custom_node,
+    );
+    seed_live_agent_session(&sessions, agent.id, nid(8), sid(42));
+
+    let target = nid(9);
+    let mut input = launch_input(agent.id);
+    input.node_id = Some(target);
+    input.require_structured = true;
+    let out = launch.execute(input).await.unwrap();
+
+    assert_eq!(pty.kills(), vec![sid(42)], "old native TUI PTY is closed");
+    assert!(
+        sessions
+            .session_for_agent_in_project(project().id, &agent.id)
+            .is_none(),
+        "old PTY registration is removed before the custom transition returns"
+    );
+    assert_eq!(
+        factory.starts(),
+        Vec::<ProfileId>::new(),
+        "existing custom session is resumed, not restarted"
+    );
+    assert_eq!(out.session.id, sid(555));
+    assert_eq!(out.session.node_id, target);
+    assert_eq!(
+        structured.node_for_agent_in_project(project().id, &agent.id),
+        Some(target),
+        "stale custom host node is rebound to the requested surface"
+    );
+    assert!(
+        out.structured.is_some(),
+        "backend still returns a chat session descriptor"
+    );
+}
+
 #[tokio::test]
 async fn launch_agent_structured_forwards_resolved_effort_ahead_of_profile_default() {
     let profile = profile(