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

crates/application/src/agent/lifecycle.rs

@@ -1937,11 +1937,20 @@ impl LaunchAgent {
                 {
                     let host_node =
                         structured.node_for_agent_in_project(input.project.id, &input.agent_id);
-                    let node_id = match reattach_decision(
+                    let decision = if input.require_structured {
-                        input.node_id,
+                        input
-                        host_node,
+                            .node_id
-                        input.conversation_id.as_deref(),
+                            .or(host_node)
-                    ) {
+                            .map(|node_id| ReattachDecision::Rebind { node_id })
+                            .unwrap_or(ReattachDecision::Idempotent)
+                    } else {
+                        reattach_decision(
+                            input.node_id,
+                            host_node,
+                            input.conversation_id.as_deref(),
+                        )
+                    };
+                    let node_id = match decision {
                         ReattachDecision::Rebind { node_id } => {
                             let _ = structured.rebind_agent_node_in_project(
                                 input.project.id,

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(

frontend/src/features/layout/LayoutGrid.chat.test.tsx

@@ -159,7 +159,7 @@ describe("LayoutGrid custom agent CLI (#147)", () => {
     await waitFor(() =>
       expect(screen.getByRole("alertdialog", { name: "Confirmer le changement de CLI" })).toBeTruthy(),
     );
-    fireEvent.click(screen.getByText("Arrêter et relancer"));
+    fireEvent.click(screen.getByText("Basculer"));
     await waitFor(() =>
       expect(screen.getByTestId("custom-agent-chat-view")).toBeTruthy(),
     );
@@ -264,7 +264,7 @@ describe("LayoutGrid custom agent CLI (#147)", () => {
     await waitFor(() =>
       expect(screen.getByRole("alertdialog", { name: "Confirmer le changement de CLI" })).toBeTruthy(),
     );
-    fireEvent.click(screen.getByText("Arrêter et relancer"));
+    fireEvent.click(screen.getByText("Basculer"));
 
     await waitFor(() =>
       expect(closeChat).toHaveBeenCalledWith(expect.stringMatching(/^mock-agent-chat-/)),
@@ -273,13 +273,26 @@ describe("LayoutGrid custom agent CLI (#147)", () => {
     await waitFor(() => expect(screen.getByTestId("terminal-view")).toBeTruthy());
   });
 
-  it("requires confirmation before switching a live native TUI session", async () => {
+  it("switches a live native TUI session to custom CLI without stopping it first (#189)", async () => {
-    renderGrid(await seeded(structuredProfile));
+    const gateways = await seeded(structuredProfile);
+    const agent = gateways.agent as MockAgentGateway;
+    const terminal = gateways.terminal as MockTerminalGateway;
+    const layout = gateways.layout as MockLayoutGateway;
+    const leafId = leaves(await layout.loadLayout("p1"))[0].id;
+    const stopLive = vi.spyOn(agent, "stopLiveAgent");
+    const closeTerminal = vi.spyOn(terminal, "closeTerminal");
+    const launchChat = vi.spyOn(agent, "launchAgentChat");
+
+    renderGrid(gateways);
 
     await waitFor(() => expect(screen.getByText("CLI custom")).toBeTruthy());
     await waitFor(() =>
       expect(screen.getByTestId("terminal-view")).toBeTruthy(),
     );
+    await waitFor(async () => {
+      const updated = await layout.loadLayout("p1");
+      expect(leaves(updated)[0].session).toMatch(/^mock-agent-session-/);
+    });
 
     fireEvent.click(screen.getByText("CLI custom"));
 
@@ -288,10 +301,18 @@ describe("LayoutGrid custom agent CLI (#147)", () => {
     );
     expect(screen.getByText(/Une reprise est possible/)).toBeTruthy();
 
-    fireEvent.click(screen.getByText("Arrêter et relancer"));
+    fireEvent.click(screen.getByText("Basculer"));
     await waitFor(() =>
       expect(screen.getByTestId("custom-agent-chat-view")).toBeTruthy(),
     );
+    expect(stopLive).not.toHaveBeenCalled();
+    expect(closeTerminal).not.toHaveBeenCalled();
+    await waitFor(() => expect(launchChat).toHaveBeenCalled());
+    expect(launchChat.mock.calls.at(-1)?.[2]).toMatchObject({ nodeId: leafId });
+    await waitFor(async () => {
+      const updated = await layout.loadLayout("p1");
+      expect(leaves(updated)[0].session).toMatch(/^mock-agent-chat-/);
+    });
   });
 
   it("keeps a restored custom CLI mode while the agent/profile catalog is still loading (#149)", async () => {

frontend/src/features/layout/LayoutGrid.tsx

@@ -701,8 +701,13 @@ function LeafView({
     await vm.setSession(id, nextSession);
   }
 
-  async function stopCurrentSessionForSwitch(): Promise<void> {
+  async function prepareSessionForModeSwitch(target: AgentCellMode): Promise<void> {
     if (!session) return;
+    if (target === "custom") {
+      await setSessionWithInstrumentation("mode-switch", null);
+      refreshLive();
+      return;
+    }
     if (cellMode === "custom" && agentGateway?.closeAgentChat) {
       await agentGateway.closeAgentChat(session);
     } else if (agentId && agentGateway?.stopLiveAgent) {
@@ -721,7 +726,7 @@ function LeafView({
     if (!target) return;
     setBusyNotice(null);
     try {
-      await stopCurrentSessionForSwitch();
+      await prepareSessionForModeSwitch(target);
       setCellMode(target);
       setPendingModeSwitch(null);
     } catch (err) {
@@ -1522,16 +1527,16 @@ function LeafView({
               Changer de CLI agent
             </h2>
             <p style={{ margin: "8px 0 0", fontSize: 12, color: "var(--color-content-muted, #9a9a9a)" }}>
-              La session courante va être arrêtée avant de relancer{" "}
+              IdeA va basculer cette cellule vers{" "}
               {pendingModeSwitch.target === "custom"
                 ? "la CLI custom"
                 : "la TUI native"}
-              .
+              {" "}et reprendre la session depuis cette surface.
             </p>
             <p style={{ margin: "8px 0 0", fontSize: 12, color: "var(--color-warning, #d49b3a)" }}>
               {conversationId
                 ? "Une reprise est possible si le profil et le backend conservent cette conversation."
-                : "Aucune conversation reprenable n'est enregistrée pour cette cellule; la relance repartira à neuf."}
+                : "Aucune conversation reprenable n'est enregistrée pour cette cellule; la bascule repartira à neuf si le backend ne peut pas reprendre."}
             </p>
             <div
               style={{
@@ -1567,7 +1572,7 @@ function LeafView({
                   cursor: "pointer",
                 }}
               >
-                Arrêter et relancer
+                Basculer
               </button>
             </div>
           </div>