fix(application,backend,app-tauri,frontend): réconcilie l'état idle et les Finals après Stop — #357 (QA verte)

Cause: après un cancel manuel de tour, le ticket médié busy/FIFO n'était pas
retiré (l'agent restait Busy, bouton Stop persistant) et un terminal tardif du
tour annulé pouvait bloquer le tour suivant (Final non affiché).

Backend: StructuredSessions lie chaque génération de tour à son ticket médié
(bind_turn_accounting) et request_turn_cancel restitue l'identité (agent,
ticket) exacte observée avant annulation; CancelAgentChat.with_turn_accounting
retire le ticket exact (cancel_head + mark_idle) seulement s'il est toujours
le ticket courant — jamais un successeur déjà remplacé;
StructuredHumanTurnGuard expose accounting_identity et agent_send (app-tauri)
lie la comptabilité au démarrage du tour humain.

Frontend: CustomAgentChatView réconcilie l'interaction active depuis le
work-state (agent idle sans délégation -> interaction terminée, fallback
« Tour terminé sans réponse finale. ») au lieu de laisser un agentBusyChanged
sans tour-id clore un tour plus récent; les terminaux tardifs (final/error) du
tour read-model-settled remplacent le fallback; tour suivant isolé des
callbacks tardifs de la génération précédente.

Tests: cancel_agent_chat (retrait du ticket exact avant le prompt suivant,
nettoyage tardif sans idle sur ticket successeur), CustomAgentChatView
(isolation tour suivant, réconciliation work-state + remplacement fallback par
Final tardif).

Réserve non bloquante: alignement fixture skills préexistant porté par le
commit test dédié 83659d9a.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/app-tauri/src/commands.rs

@@ -2901,6 +2901,15 @@ pub async fn agent_send(
             "agent_send",
         )
     });
+    if let Some((agent, ticket)) = turn_guard
+        .as_ref()
+        .and_then(backend::StructuredHumanTurnGuard::accounting_identity)
+    {
+        let _ =
+            state
+                .structured_sessions
+                .bind_turn_accounting(&sid, turn_generation, agent, ticket);
+    }
 
     // Retain the human submit in the same live scrollback as model chunks so
     // `reattach_agent_chat` can repaint the whole in-flight conversation.

crates/application/src/terminal/registry.rs

@@ -10,8 +10,11 @@ use std::collections::HashMap;
 use std::sync::{Arc, Mutex};
 
 use domain::conversation::ConversationId;
+use domain::mailbox::TicketId;
 use domain::ports::{AgentSession, PtyHandle};
-use domain::{AgentId, IssueRef, NodeId, ProjectId, SessionId, SessionKind, TerminalSession};
+use domain::{
+    AgentId, IssueRef, NodeId, ProjectId, RuntimeAgentKey, SessionId, SessionKind, TerminalSession,
+};
 
 use crate::model_server::ModelServerUseGuard;
 
@@ -541,6 +544,8 @@ struct StructuredEntry {
     turn_generation: u64,
     /// Current/last logical-turn state for idempotent request cancellation.
     turn_state: StructuredTurnState,
+    /// Exact mediated ticket owned by the active generation, when it acquired one.
+    turn_accounting: Option<(u64, RuntimeAgentKey, TicketId)>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -673,6 +678,7 @@ impl StructuredSessions {
                     _model_server_guard: model_server_guard,
                     turn_generation: 0,
                     turn_state: StructuredTurnState::Completed,
+                    turn_accounting: None,
                 },
             );
         }
@@ -712,10 +718,31 @@ impl StructuredSessions {
             entry.turn_generation = entry.turn_generation.wrapping_add(1).max(1);
             let generation = entry.turn_generation;
             entry.turn_state = StructuredTurnState::Active(generation);
+            entry.turn_accounting = None;
             Some(generation)
         })
     }
 
+    /// Correlates one logical provider generation with its mediated busy/FIFO ticket.
+    pub fn bind_turn_accounting(
+        &self,
+        id: &SessionId,
+        generation: u64,
+        agent: RuntimeAgentKey,
+        ticket: TicketId,
+    ) -> bool {
+        self.entries.lock().ok().is_some_and(|mut entries| {
+            let Some(entry) = entries.get_mut(id) else {
+                return false;
+            };
+            if entry.turn_state != StructuredTurnState::Active(generation) {
+                return false;
+            }
+            entry.turn_accounting = Some((generation, agent, ticket));
+            true
+        })
+    }
+
     /// Atomically records a cancellation request and returns the live session.
     pub fn request_turn_cancel(
         &self,
@@ -723,6 +750,7 @@ impl StructuredSessions {
     ) -> Option<(
         Arc<dyn AgentSession>,
         domain::ports::CancelCurrentTurnOutcome,
+        Option<(RuntimeAgentKey, TicketId)>,
     )> {
         self.entries.lock().ok().and_then(|mut entries| {
             let entry = entries.get_mut(id)?;
@@ -738,7 +766,14 @@ impl StructuredSessions {
                     domain::ports::CancelCurrentTurnOutcome::AlreadyCompleted
                 }
             };
-            Some((Arc::clone(&entry.session), outcome))
+            let accounting = match entry.turn_state {
+                StructuredTurnState::Cancelled(generation) => entry
+                    .turn_accounting
+                    .filter(|(bound, _, _)| *bound == generation)
+                    .map(|(_, agent, ticket)| (agent, ticket)),
+                StructuredTurnState::Completed | StructuredTurnState::Active(_) => None,
+            };
+            Some((Arc::clone(&entry.session), outcome, accounting))
         })
     }
 
@@ -758,6 +793,7 @@ impl StructuredSessions {
             if let Some(entry) = entries.get_mut(id) {
                 if entry.turn_state == StructuredTurnState::Active(generation) {
                     entry.turn_state = StructuredTurnState::Completed;
+                    entry.turn_accounting = None;
                 }
             }
         }

crates/application/src/terminal/usecases.rs

@@ -2,6 +2,8 @@
 
 use std::sync::Arc;
 
+use domain::input::InputMediator;
+use domain::mailbox::AgentMailbox;
 use domain::ports::{CancelCurrentTurnOutcome, EventBus, PtyPort, SpawnSpec};
 use domain::{
     AgentId, DomainEvent, NodeId, Project, ProjectPath, PtySize, SessionId, SessionKind,
@@ -27,13 +29,28 @@ pub struct CancelAgentChatOutput {
 /// Cancels one structured chat turn without stopping its reusable runtime.
 pub struct CancelAgentChat {
     sessions: Arc<StructuredSessions>,
+    turn_accounting: Option<(Arc<dyn InputMediator>, Arc<dyn AgentMailbox>)>,
 }
 
 impl CancelAgentChat {
     /// Builds the use case from the structured runtime registry.
     #[must_use]
     pub fn new(sessions: Arc<StructuredSessions>) -> Self {
-        Self { sessions }
+        Self {
+            sessions,
+            turn_accounting: None,
+        }
+    }
+
+    /// Wires the mediated busy/FIFO state owned by direct human turns.
+    #[must_use]
+    pub fn with_turn_accounting(
+        mut self,
+        input: Arc<dyn InputMediator>,
+        mailbox: Arc<dyn AgentMailbox>,
+    ) -> Self {
+        self.turn_accounting = Some((input, mailbox));
+        self
     }
 
     /// Requests cancellation from the live session and deliberately leaves its
@@ -43,7 +60,7 @@ impl CancelAgentChat {
     /// Returns [`AppError::NotFound`] only when the session itself is absent, and
     /// a process error when the adapter could not interrupt its current child.
     pub async fn execute(&self, session_id: SessionId) -> Result<CancelAgentChatOutput, AppError> {
-        let (session, outcome) = self
+        let (session, outcome, active_ticket) = self
             .sessions
             .request_turn_cancel(&session_id)
             .ok_or_else(|| AppError::NotFound(format!("structured session {session_id}")))?;
@@ -52,6 +69,18 @@ impl CancelAgentChat {
                 self.sessions.restore_turn_after_cancel_failure(&session_id);
                 return Err(AppError::from(error));
             }
+            if let (Some((agent, ticket)), Some((input, mailbox))) =
+                (active_ticket, self.turn_accounting.as_ref())
+            {
+                // The provider kill can race the old pump's normal guard cleanup and
+                // a caller may already have started the next turn. Retire only the
+                // exact ticket observed before cancellation; never mark a successor
+                // idle when it has already replaced that ticket.
+                if input.busy_state(agent).ticket() == Some(ticket) {
+                    mailbox.cancel_head(agent, ticket);
+                    input.mark_idle(agent);
+                }
+            }
         }
         Ok(CancelAgentChatOutput {
             session_id,

crates/application/tests/cancel_agent_chat.rs

@@ -5,13 +5,16 @@ use application::{
     CancelAgentChat, LiveRuntimeState, LiveSessions, StructuredSessions, TerminalSessions,
 };
 use async_trait::async_trait;
+use domain::input::{AgentBusyState, InputMediator, SubmitConfig};
+use domain::mailbox::{AgentMailbox, MailboxError, PendingReply, Ticket, TicketId};
 use domain::ports::{AgentSession, AgentSessionError, CancelCurrentTurnOutcome, ReplyStream};
-use domain::{AgentId, NodeId, ProjectId, SessionId};
+use domain::{AgentId, NodeId, ProjectId, RuntimeAgentKey, SessionId};
 use uuid::Uuid;
 
 struct FakeSession {
     id: SessionId,
     cancellations: Mutex<VecDeque<CancelCurrentTurnOutcome>>,
+    cancel_hook: Mutex<Option<Box<dyn FnOnce() + Send>>>,
     sends: Mutex<Vec<String>>,
     shutdowns: Mutex<usize>,
 }
@@ -21,10 +24,16 @@ impl FakeSession {
         Self {
             id,
             cancellations: Mutex::new(outcomes.into_iter().collect()),
+            cancel_hook: Mutex::new(None),
             sends: Mutex::new(Vec::new()),
             shutdowns: Mutex::new(0),
         }
     }
+
+    fn with_cancel_hook(self, hook: impl FnOnce() + Send + 'static) -> Self {
+        *self.cancel_hook.lock().unwrap() = Some(Box::new(hook));
+        self
+    }
 }
 
 #[async_trait]
@@ -43,12 +52,16 @@ impl AgentSession for FakeSession {
     }
 
     async fn cancel_current_turn(&self) -> Result<CancelCurrentTurnOutcome, AgentSessionError> {
-        Ok(self
+        let outcome = self
             .cancellations
             .lock()
             .unwrap()
             .pop_front()
-            .unwrap_or(CancelCurrentTurnOutcome::AlreadyCompleted))
+            .unwrap_or(CancelCurrentTurnOutcome::AlreadyCompleted);
+        if let Some(hook) = self.cancel_hook.lock().unwrap().take() {
+            hook();
+        }
+        Ok(outcome)
     }
 
     async fn shutdown(&self) -> Result<(), AgentSessionError> {
@@ -61,6 +74,58 @@ fn id<T>(value: u128, make: impl FnOnce(Uuid) -> T) -> T {
     make(Uuid::from_u128(value))
 }
 
+struct TurnAccounting {
+    state: Mutex<AgentBusyState>,
+    cancelled: Mutex<Vec<(RuntimeAgentKey, TicketId)>>,
+}
+
+impl Default for TurnAccounting {
+    fn default() -> Self {
+        Self {
+            state: Mutex::new(AgentBusyState::Idle),
+            cancelled: Mutex::new(Vec::new()),
+        }
+    }
+}
+
+impl InputMediator for TurnAccounting {
+    fn enqueue(&self, _agent: RuntimeAgentKey, _ticket: Ticket) -> PendingReply {
+        panic!("not used")
+    }
+
+    fn bind_handle_with_submit(
+        &self,
+        _agent: RuntimeAgentKey,
+        _handle: domain::ports::PtyHandle,
+        _submit: SubmitConfig,
+    ) {
+    }
+
+    fn preempt(&self, _agent: RuntimeAgentKey) {}
+
+    fn mark_idle(&self, _agent: RuntimeAgentKey) {
+        *self.state.lock().unwrap() = AgentBusyState::Idle;
+    }
+
+    fn busy_state(&self, _agent: RuntimeAgentKey) -> AgentBusyState {
+        *self.state.lock().unwrap()
+    }
+}
+
+impl AgentMailbox for TurnAccounting {
+    fn enqueue(&self, _agent: RuntimeAgentKey, _ticket: Ticket) -> PendingReply {
+        panic!("not used")
+    }
+
+    fn resolve(&self, agent: RuntimeAgentKey, _result: String) -> Result<(), MailboxError> {
+        Err(MailboxError::NoPendingRequest(agent.agent_id))
+    }
+
+    fn cancel_head(&self, agent: RuntimeAgentKey, ticket_id: TicketId) {
+        self.cancelled.lock().unwrap().push((agent, ticket_id));
+    }
+}
+
 #[tokio::test]
 async fn cancel_keeps_session_and_accepts_a_second_prompt_without_shutdown() {
     let session_id = id(1, SessionId::from_uuid);
@@ -140,3 +205,89 @@ async fn double_cancel_is_typed_and_missing_session_remains_distinct() {
     assert_eq!(error.code(), "NOT_FOUND");
     assert!(sessions.session(&session_id).is_some());
 }
+
+#[tokio::test]
+async fn cancel_retires_the_exact_busy_turn_before_the_next_prompt() {
+    let session_id = id(20, SessionId::from_uuid);
+    let project_id = id(21, ProjectId::from_uuid);
+    let agent_id = id(22, AgentId::from_uuid);
+    let ticket = TicketId::from_uuid(Uuid::from_u128(23));
+    let accounting = Arc::new(TurnAccounting::default());
+    *accounting.state.lock().unwrap() = AgentBusyState::Busy {
+        ticket,
+        since_ms: 1,
+    };
+    let session = Arc::new(FakeSession::new(
+        session_id,
+        [CancelCurrentTurnOutcome::Cancelled],
+    ));
+    let sessions = Arc::new(StructuredSessions::new());
+    sessions.insert_in_project(project_id, session, agent_id, id(24, NodeId::from_uuid));
+    let generation = sessions.begin_turn(&session_id).unwrap();
+    assert!(sessions.bind_turn_accounting(
+        &session_id,
+        generation,
+        RuntimeAgentKey::new(project_id, agent_id),
+        ticket,
+    ));
+    let input = Arc::clone(&accounting) as Arc<dyn InputMediator>;
+    let mailbox = Arc::clone(&accounting) as Arc<dyn AgentMailbox>;
+    let cancel = CancelAgentChat::new(Arc::clone(&sessions)).with_turn_accounting(input, mailbox);
+
+    let output = cancel.execute(session_id).await.unwrap();
+
+    assert_eq!(output.outcome, CancelCurrentTurnOutcome::Cancelled);
+    assert_eq!(*accounting.state.lock().unwrap(), AgentBusyState::Idle);
+    assert_eq!(
+        *accounting.cancelled.lock().unwrap(),
+        [(RuntimeAgentKey::new(project_id, agent_id), ticket)]
+    );
+}
+
+#[tokio::test]
+async fn late_cancel_cleanup_does_not_mark_a_successor_ticket_idle() {
+    let session_id = id(30, SessionId::from_uuid);
+    let project_id = id(31, ProjectId::from_uuid);
+    let agent_id = id(32, AgentId::from_uuid);
+    let cancelled_ticket = TicketId::from_uuid(Uuid::from_u128(33));
+    let successor_ticket = TicketId::from_uuid(Uuid::from_u128(34));
+    let accounting = Arc::new(TurnAccounting::default());
+    *accounting.state.lock().unwrap() = AgentBusyState::Busy {
+        ticket: cancelled_ticket,
+        since_ms: 1,
+    };
+    let accounting_during_cancel = Arc::clone(&accounting);
+    let session = Arc::new(
+        FakeSession::new(session_id, [CancelCurrentTurnOutcome::Cancelled]).with_cancel_hook(
+            move || {
+                *accounting_during_cancel.state.lock().unwrap() = AgentBusyState::Busy {
+                    ticket: successor_ticket,
+                    since_ms: 2,
+                };
+            },
+        ),
+    );
+    let sessions = Arc::new(StructuredSessions::new());
+    sessions.insert_in_project(project_id, session, agent_id, id(35, NodeId::from_uuid));
+    let generation = sessions.begin_turn(&session_id).unwrap();
+    assert!(sessions.bind_turn_accounting(
+        &session_id,
+        generation,
+        RuntimeAgentKey::new(project_id, agent_id),
+        cancelled_ticket,
+    ));
+    let input = Arc::clone(&accounting) as Arc<dyn InputMediator>;
+    let mailbox = Arc::clone(&accounting) as Arc<dyn AgentMailbox>;
+    let cancel = CancelAgentChat::new(Arc::clone(&sessions)).with_turn_accounting(input, mailbox);
+
+    cancel.execute(session_id).await.unwrap();
+
+    assert_eq!(
+        *accounting.state.lock().unwrap(),
+        AgentBusyState::Busy {
+            ticket: successor_ticket,
+            since_ms: 2,
+        }
+    );
+    assert!(accounting.cancelled.lock().unwrap().is_empty());
+}

crates/backend/src/lib.rs

@@ -1774,6 +1774,16 @@ impl StructuredHumanTurnGuard {
         }
     }
 
+    /// Exact mediated ticket owned by this logical human turn, if it acquired Busy.
+    #[must_use]
+    pub fn accounting_identity(
+        &self,
+    ) -> Option<(domain::RuntimeAgentKey, domain::mailbox::TicketId)> {
+        self.armed
+            .load(std::sync::atomic::Ordering::Acquire)
+            .then_some((self.agent, self.ticket_id))
+    }
+
     /// Resolves whether a concrete provider terminal event really ends the
     /// logical human turn. During self-restart it waits for the replacement
     /// session, then acknowledges the handoff so the scheduler can complete.
@@ -2757,7 +2767,6 @@ impl BackendCore {
         // `profile.structured_adapter`. Injectés dans LaunchAgent (routage §17.4) et
         // ChangeAgentProfile (shutdown polymorphe au hot-swap).
         let structured_sessions = Arc::new(StructuredSessions::new());
-        let cancel_agent_chat = Arc::new(CancelAgentChat::new(Arc::clone(&structured_sessions)));
         let live_sessions = Arc::new(LiveSessions::new(
             Arc::clone(&terminal_sessions),
             Arc::clone(&structured_sessions),
@@ -3739,6 +3748,10 @@ impl BackendCore {
             });
         }
         let input_mediator = Arc::clone(&mediated_inbox) as Arc<dyn domain::input::InputMediator>;
+        let cancel_agent_chat = Arc::new(
+            CancelAgentChat::new(Arc::clone(&structured_sessions))
+                .with_turn_accounting(Arc::clone(&input_mediator), Arc::clone(&mailbox)),
+        );
         let background_tasks = Arc::new(AppBackgroundTaskStore::new(Arc::clone(&store_port)));
         let background_tasks_port = Arc::clone(&background_tasks) as Arc<dyn BackgroundTaskStore>;
         let (background_ready_tx, mut background_ready_rx) =

frontend/src/features/agents/CustomAgentChatView.test.tsx

@@ -1780,6 +1780,112 @@ describe("CustomAgentChatView", () => {
     expect(screen.queryByRole("button", { name: "Stop" })).toBeNull();
   });
 
+  it("keeps a following turn isolated from a late terminal callback of the previous turn (#357)", async () => {
+    const harness = createStreamingAgentHarness();
+
+    render(
+      <DIProvider
+        gateways={{
+          agent: harness.agent,
+          system: { pickFile: vi.fn(async () => null) },
+        } as unknown as Gateways}
+      >
+        <CustomAgentChatView
+          projectId="project-1"
+          agentId="agent-1"
+          agentName="Worker"
+          profile={profile}
+          cwd="/repo"
+          nodeId="node-1"
+          sessionId="chat-session-1"
+          conversationId="conversation-1"
+          onSessionId={vi.fn()}
+          onConversationId={vi.fn()}
+        />
+      </DIProvider>,
+    );
+
+    const composer = await screen.findByLabelText(/Message CLI personnalisée/);
+    fireEvent.change(composer, { target: { value: "first turn" } });
+    fireEvent.click(screen.getByRole("button", { name: "Envoyer" }));
+    await waitFor(() => expect(harness.emitterCount()).toBe(1));
+    act(() => harness.emit(0, { kind: "final", content: "First final" }));
+    await screen.findByText("First final");
+
+    fireEvent.change(composer, { target: { value: "second turn" } });
+    fireEvent.click(screen.getByRole("button", { name: "Envoyer" }));
+    await waitFor(() => expect(harness.emitterCount()).toBe(2));
+
+    act(() => harness.emit(0, { kind: "final", content: "Late first final" }));
+    expect(screen.queryByText("Late first final")).toBeNull();
+    expect(screen.getByRole("button", { name: "Stop" })).toBeTruthy();
+
+    act(() => harness.emit(1, { kind: "final", content: "Second final" }));
+    expect(await screen.findByText("Second final")).toBeTruthy();
+    expect(screen.queryByRole("button", { name: "Stop" })).toBeNull();
+    expect(screen.getByRole("button", { name: "Envoyer" })).toBeTruthy();
+  });
+
+  it("reconciles an active composer from the terminal work-state and replaces its fallback with a late Final (#357)", async () => {
+    const harness = createStreamingAgentHarness();
+    const system = new MockSystemGateway();
+    const workState = new MockWorkStateGateway();
+    const stateFor = (busy: boolean) => ({
+      agents: [
+        {
+          agentId: "agent-1",
+          name: "Worker",
+          profileId: "structured",
+          busy: busy
+            ? ({ state: "busy", ticket: "turn-357", sinceMs: 1 } as const)
+            : ({ state: "idle" } as const),
+          tickets: [],
+        },
+      ],
+      conversations: [],
+    });
+    workState._setProjectWorkState("project-1", stateFor(false));
+
+    render(
+      <DIProvider
+        gateways={{ agent: harness.agent, system, workState } as unknown as Gateways}
+      >
+        <CustomAgentChatView
+          projectId="project-1"
+          agentId="agent-1"
+          agentName="Worker"
+          profile={profile}
+          cwd="/repo"
+          nodeId="node-1"
+          sessionId="chat-session-1"
+          conversationId="conversation-1"
+          onSessionId={vi.fn()}
+          onConversationId={vi.fn()}
+        />
+      </DIProvider>,
+    );
+
+    const composer = await screen.findByLabelText(/Message CLI personnalisée/);
+    await waitFor(() => expect(screen.getByRole("button", { name: "Envoyer" })).toBeTruthy());
+    workState._setProjectWorkState("project-1", stateFor(true));
+    fireEvent.change(composer, { target: { value: "turn without projected final" } });
+    fireEvent.click(screen.getByRole("button", { name: "Envoyer" }));
+    await waitFor(() => expect(harness.emitterCount()).toBe(1));
+    expect(screen.getByRole("button", { name: "Stop" })).toBeTruthy();
+
+    workState._setProjectWorkState("project-1", stateFor(false));
+    act(() => system.emit({ type: "agentBusyChanged", agentId: "agent-1", busy: false }));
+
+    expect(await screen.findByText("Tour terminé sans réponse finale.")).toBeTruthy();
+    expect(screen.queryByRole("button", { name: "Stop" })).toBeNull();
+    expect(screen.getByRole("button", { name: "Envoyer" })).toBeTruthy();
+
+    act(() => harness.emit(0, { kind: "final", content: "Recovered late final" }));
+    expect(await screen.findByText("Recovered late final")).toBeTruthy();
+    expect(screen.queryByText("Tour terminé sans réponse finale.")).toBeNull();
+    expect(screen.queryByRole("button", { name: "Stop" })).toBeNull();
+  });
+
   it.each(["alreadyCancelled", "alreadyCompleted"] as const)(
     "treats backend outcome %s as one already-stopped terminal result",
     async (outcome) => {

frontend/src/features/agents/CustomAgentChatView.tsx

@@ -104,6 +104,10 @@ const chatMessageQueueCache = new Map<string, QueuedChatMessage[]>();
 const CHAT_ATTACHMENT_DRAFT_CACHE_LIMIT = 24;
 const CHAT_MESSAGE_QUEUE_CACHE_LIMIT = 24;
 const EMPTY_MODEL_RESPONSE_MESSAGE = "Le modèle n'a renvoyé aucune réponse.";
+const MODEL_RESPONSE_NOT_FINALIZED_MESSAGE =
+  "La réponse du modèle n'a pas pu être finalisée.";
+const TURN_FINISHED_WITHOUT_FINAL_MESSAGE =
+  "Tour terminé sans réponse finale.";
 const COMPOSER_RESIZE_STEP = 12;
 const FALLBACK_COMPOSER_HEIGHT = 64;
 const COMPOSER_HISTORY_LIMIT = 100;
@@ -717,7 +721,11 @@ function completeChatViewProgress(state: ChatViewState): ChatViewState {
 }
 
 function isRecoverableNoResponseTurn(turn: ChatTurn | undefined): boolean {
-  return turn?.role === "error" && turn.text === EMPTY_MODEL_RESPONSE_MESSAGE;
+  return (
+    turn?.role === "error" &&
+    (turn.text === EMPTY_MODEL_RESPONSE_MESSAGE ||
+      turn.text === TURN_FINISHED_WITHOUT_FINAL_MESSAGE)
+  );
 }
 
 function turnsIndicateBusy(state: ChatViewState): boolean {
@@ -949,7 +957,10 @@ function foldChunk(
       if (last?.role === "agent") next[next.length - 1] = { ...last, pending: false };
       next.push({
         role: "error",
-        text: String(raw.message ?? "Erreur agent"),
+        text:
+          String(raw.message ?? "Erreur agent") === MODEL_RESPONSE_NOT_FINALIZED_MESSAGE
+            ? TURN_FINISHED_WITHOUT_FINAL_MESSAGE
+            : String(raw.message ?? "Erreur agent"),
         receivedAtMs: emittedAtMs,
       });
       return { ...completedState, turns: next };
@@ -1097,6 +1108,7 @@ export function CustomAgentChatView({
   const draftSaveSeqRef = useRef(0);
   const interactionSeqRef = useRef(0);
   const activeInteractionIdRef = useRef<string | null>(null);
+  const readModelSettledInteractionIdRef = useRef<string | null>(null);
   const transmissionInFlightRef = useRef(false);
   const cancelledInteractionIdsRef = useRef(new Set<string>());
   const ignoreUnscopedChunksAfterStopRef = useRef(false);
@@ -1290,6 +1302,7 @@ export function CustomAgentChatView({
 
   const refreshRequesterDelegation = useCallback(async () => {
     const refreshSeq = ++requesterRefreshSeqRef.current;
+    const interactionAtRefresh = activeInteractionIdRef.current;
     if (!workState) {
       if (refreshSeq !== requesterRefreshSeqRef.current) return;
       setRequesterDelegation({
@@ -1322,6 +1335,26 @@ export function CustomAgentChatView({
         currentAgentBusy,
         delegationTargetName: target ? workAgentDisplayName(target) : null,
       });
+      if (
+        interactionAtRefresh &&
+        activeInteractionIdRef.current === interactionAtRefresh &&
+        !currentAgentBusy &&
+        !target
+      ) {
+        markProjectCliInteractionFinished(projectId, interactionAtRefresh);
+        activeInteractionIdRef.current = null;
+        readModelSettledInteractionIdRef.current = interactionAtRefresh;
+        stopTerminalOverrideRef.current = true;
+        setStopTerminalOverride(true);
+        setBusy(false);
+        setQueueDrainReady(false);
+        updateChatViewState((previous) =>
+          foldChunk(previous, {
+            kind: "error",
+            message: TURN_FINISHED_WITHOUT_FINAL_MESSAGE,
+          }),
+        );
+      }
       if (stopTerminalOverrideRef.current && !currentAgentBusy && !target) {
         stopTerminalOverrideRef.current = false;
         setStopTerminalOverride(false);
@@ -1333,7 +1366,7 @@ export function CustomAgentChatView({
         delegationTargetName: null,
       });
     }
-  }, [agentId, projectId, workState]);
+  }, [agentId, projectId, updateChatViewState, workState]);
 
   const clearPersistedDraft = useCallback(async () => {
     if (!draftScope) return;
@@ -1510,17 +1543,9 @@ export function CustomAgentChatView({
           event.type === "agentInboxChanged" ||
           event.type === "agentWakeChanged"
         ) {
-          if (
+          // Reconcile through the current work-state snapshot below. A domain
-            event.type === "agentBusyChanged" &&
+          // event carries no turn id and may belong to a previously cancelled
-            event.agentId === agentId &&
+          // generation, so it must never settle a newer local turn directly.
-            !event.busy
-          ) {
-            if (activeInteractionIdRef.current) {
-              markProjectCliInteractionFinished(projectId, activeInteractionIdRef.current);
-              activeInteractionIdRef.current = null;
-            }
-            setBusy(false);
-          }
           void refreshRequesterDelegation();
         }
       })
@@ -1590,11 +1615,18 @@ export function CustomAgentChatView({
 
   const receive = useCallback(
     (chunk: ReplyChunk, sourceInteractionId?: string) => {
-      if (
+      if (sourceInteractionId) {
-        sourceInteractionId &&
+        const isLateTerminalForReadModelSettledTurn =
-        cancelledInteractionIdsRef.current.has(sourceInteractionId)
+          activeInteractionIdRef.current === null &&
-      ) {
+          readModelSettledInteractionIdRef.current === sourceInteractionId &&
-        return;
+          (chunk.kind === "final" || chunk.kind === "error");
+        if (
+          cancelledInteractionIdsRef.current.has(sourceInteractionId) ||
+          (activeInteractionIdRef.current !== sourceInteractionId &&
+            !isLateTerminalForReadModelSettledTurn)
+        ) {
+          return;
+        }
       }
       if (!sourceInteractionId && ignoreUnscopedChunksAfterStopRef.current) {
         if (chunk.kind === "userPrompt") {
@@ -1617,13 +1649,12 @@ export function CustomAgentChatView({
         ) {
           markProjectCliInteractionStarted(projectId, activeInteractionId);
         }
-        if (chunk.progress.stage === "completed") {
-          markProjectCliInteractionFinished(projectId, activeInteractionId);
-          activeInteractionIdRef.current = null;
-        }
       }
       updateChatViewState((prev) => foldChunk(prev, chunk));
       if (chunk.kind === "final" || chunk.kind === "error") {
+        if (sourceInteractionId) {
+          readModelSettledInteractionIdRef.current = null;
+        }
         setQueueDrainReady(chunk.kind === "final");
         if (activeInteractionIdRef.current) {
           markProjectCliInteractionFinished(projectId, activeInteractionIdRef.current);
@@ -2505,11 +2536,15 @@ export function CustomAgentChatView({
     stopTerminalOverrideRef.current = false;
     setStopTerminalOverride(false);
     activeInteractionIdRef.current = interactionId;
+    readModelSettledInteractionIdRef.current = null;
     markProjectCliInteractionStarted(projectId, interactionId);
-    const finishInteraction = () => {
+    const failInteraction = () => {
       if (activeInteractionIdRef.current !== interactionId) return;
       markProjectCliInteractionFinished(projectId, interactionId);
       activeInteractionIdRef.current = null;
+      if (readModelSettledInteractionIdRef.current === interactionId) {
+        readModelSettledInteractionIdRef.current = null;
+      }
     };
     threadScroll.followLatest();
     setBusy(true);
@@ -2542,7 +2577,6 @@ export function CustomAgentChatView({
         }));
       await sendTurn(sid);
       if (cancelledInteractionIdsRef.current.has(interactionId)) return;
-      finishInteraction();
     } catch (e) {
       if (cancelledInteractionIdsRef.current.has(interactionId)) return;
       if (isNotFound(e)) {
@@ -2554,10 +2588,9 @@ export function CustomAgentChatView({
             retryAttachNotFound: true,
           });
           await sendTurn(recoveredSession);
-          finishInteraction();
           return;
         } catch (recoveryError) {
-          finishInteraction();
+          failInteraction();
           setBusy(false);
           setQueueDrainReady(false);
           setError({ message: describe(recoveryError), openFailure: false });
@@ -2571,7 +2604,7 @@ export function CustomAgentChatView({
           return;
         }
       }
-      finishInteraction();
+      failInteraction();
       setBusy(false);
       setQueueDrainReady(false);
       setError({ message: describe(e), openFailure: false });
@@ -2618,6 +2651,7 @@ export function CustomAgentChatView({
     setQueueDrainReady(false);
     ignoreUnscopedChunksAfterStopRef.current = true;
     const interactionBeingCancelled = activeInteractionIdRef.current;
+    readModelSettledInteractionIdRef.current = null;
     if (interactionBeingCancelled) {
       cancelledInteractionIdsRef.current.add(interactionBeingCancelled);
     }