feat(workstate): snapshot des délégations en file par agent (Lot B backend)

Ajoute un port de lecture ségrégué `AgentQueueSnapshot` (ISP) distinct du
`AgentMailbox` mutant : il expose `queue_for(agent)` qui renvoie des
`QueuedTicketSnapshot` clonés, ordonnés FIFO, avec position recalculée
(0 = tête). Observer la file ne la mute jamais ; le one-shot reply sender
reste dans l'adaptateur.

- domain : value object `QueuedTicketSnapshot` + trait `AgentQueueSnapshot`
  (object-safe, partagé en `Arc<dyn …>`).
- infrastructure : `InMemoryMailbox` implémente la vue lecture en plus de la
  vue mutation ; positions recalculées à chaque appel.
- application : le read-model work-state liste les délégations en attente via
  ce port, troncature de l'aperçu de tâche en conservant la longueur d'origine.
- app-tauri : DTO `camelCase` des tickets en file câblé dans l'état.

Tests verts : domain mailbox (6), infrastructure mailbox (13),
application workstate (12), app-tauri dto_agents (20).

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

crates/application/tests/workstate.rs

@@ -9,16 +9,18 @@ use async_trait::async_trait;
 
 use application::{
     GetProjectWorkState, GetProjectWorkStateInput, LiveSessionKind, LiveSessions,
-    StructuredSessions, TerminalSessions,
+    StructuredSessions, TerminalSessions, TicketWorkSource, TicketWorkStatus,
+};
+use domain::mailbox::{
+    AgentQueueSnapshot, MailboxError, PendingReply, QueuedTicketSnapshot, Ticket,
 };
-use domain::mailbox::{MailboxError, PendingReply, Ticket};
 use domain::ports::{
     AgentContextStore, AgentSession, AgentSessionError, PtyHandle, ReplyStream, StoreError,
 };
 use domain::{
-    Agent, AgentBusyState, AgentId, AgentManifest, AgentOrigin, InputMediator, ManifestEntry,
-    MarkdownDoc, NodeId, ProfileId, Project, ProjectId, ProjectPath, PtySize, RemoteRef, SessionId,
-    SessionKind, TerminalSession,
+    Agent, AgentBusyState, AgentId, AgentManifest, AgentOrigin, ConversationId, InputMediator,
+    InputSource, ManifestEntry, MarkdownDoc, NodeId, ProfileId, Project, ProjectId, ProjectPath,
+    PtySize, RemoteRef, SessionId, SessionKind, TerminalSession, TicketId,
 };
 use uuid::Uuid;
 
@@ -138,6 +140,45 @@ impl InputMediator for FakeInput {
     }
 }
 
+#[derive(Default)]
+struct FakeQueue {
+    queues: Mutex<HashMap<AgentId, Vec<QueuedTicketSnapshot>>>,
+}
+
+impl FakeQueue {
+    fn set(&self, agent: AgentId, tickets: Vec<QueuedTicketSnapshot>) {
+        self.queues.lock().unwrap().insert(agent, tickets);
+    }
+}
+
+impl AgentQueueSnapshot for FakeQueue {
+    fn queue_for(&self, agent: AgentId) -> Vec<QueuedTicketSnapshot> {
+        self.queues
+            .lock()
+            .unwrap()
+            .get(&agent)
+            .cloned()
+            .unwrap_or_default()
+    }
+}
+
+fn snapshot(
+    id: u128,
+    position: u32,
+    source: InputSource,
+    requester: &str,
+    task: &str,
+) -> QueuedTicketSnapshot {
+    QueuedTicketSnapshot {
+        id: TicketId::from_uuid(Uuid::from_u128(id)),
+        source,
+        conversation: ConversationId::from_uuid(Uuid::from_u128(id + 1000)),
+        requester: requester.to_owned(),
+        task: task.to_owned(),
+        position,
+    }
+}
+
 struct FakeSession {
     id: SessionId,
 }
@@ -188,6 +229,7 @@ struct Fixture {
     pty: Arc<TerminalSessions>,
     structured: Arc<StructuredSessions>,
     input: Arc<FakeInput>,
+    queue: Arc<FakeQueue>,
     project: Project,
 }
 
@@ -197,18 +239,22 @@ fn fixture(agents: &[Agent]) -> Fixture {
     let live = Arc::new(LiveSessions::new(Arc::clone(&pty), Arc::clone(&structured)));
     let input = Arc::new(FakeInput::default());
     let input_port = Arc::clone(&input) as Arc<dyn InputMediator>;
+    let queue = Arc::new(FakeQueue::default());
+    let queue_port = Arc::clone(&queue) as Arc<dyn AgentQueueSnapshot>;
     let usecase = GetProjectWorkState::new(
         Arc::new(FakeContexts {
             manifest: manifest(agents),
         }),
         live,
         input_port,
+        queue_port,
     );
     Fixture {
         usecase,
         pty,
         structured,
         input,
+        queue,
         project: project(),
     }
 }
@@ -305,3 +351,169 @@ async fn workstate_ignores_live_agents_absent_from_manifest() {
     assert_eq!(out.agents[0].agent_id, a.id);
     assert_eq!(out.agents[0].live, None);
 }
+
+#[tokio::test]
+async fn workstate_agent_without_queue_has_no_tickets() {
+    let a = agent(10, "alpha");
+    let f = fixture(std::slice::from_ref(&a));
+
+    let out = f
+        .usecase
+        .execute(GetProjectWorkStateInput { project: f.project })
+        .await
+        .unwrap();
+
+    assert!(out.agents[0].tickets.is_empty());
+}
+
+#[tokio::test]
+async fn workstate_lists_two_tickets_in_fifo_order() {
+    let a = agent(10, "alpha");
+    let f = fixture(std::slice::from_ref(&a));
+    let from = aid(20);
+    f.queue.set(
+        a.id,
+        vec![
+            snapshot(1, 0, InputSource::agent(from), "Main", "first"),
+            snapshot(2, 1, InputSource::agent(from), "Main", "second"),
+        ],
+    );
+
+    let out = f
+        .usecase
+        .execute(GetProjectWorkStateInput { project: f.project })
+        .await
+        .unwrap();
+
+    let tickets = &out.agents[0].tickets;
+    assert_eq!(tickets.len(), 2);
+    assert_eq!(tickets[0].ticket_id, ticket_id(1));
+    assert_eq!(tickets[0].position, 0);
+    assert_eq!(tickets[1].ticket_id, ticket_id(2));
+    assert_eq!(tickets[1].position, 1);
+}
+
+#[tokio::test]
+async fn workstate_marks_busy_head_in_progress_and_rest_queued() {
+    let a = agent(10, "alpha");
+    let f = fixture(std::slice::from_ref(&a));
+    let from = aid(20);
+    f.queue.set(
+        a.id,
+        vec![
+            snapshot(1, 0, InputSource::agent(from), "Main", "first"),
+            snapshot(2, 1, InputSource::agent(from), "Main", "second"),
+        ],
+    );
+    f.input.set_busy(
+        a.id,
+        AgentBusyState::Busy {
+            ticket: ticket_id(1),
+            since_ms: 5,
+        },
+    );
+
+    let out = f
+        .usecase
+        .execute(GetProjectWorkStateInput { project: f.project })
+        .await
+        .unwrap();
+
+    let tickets = &out.agents[0].tickets;
+    assert_eq!(tickets[0].status, TicketWorkStatus::InProgress);
+    assert_eq!(tickets[1].status, TicketWorkStatus::Queued);
+}
+
+#[tokio::test]
+async fn workstate_marks_all_queued_when_agent_idle() {
+    let a = agent(10, "alpha");
+    let f = fixture(std::slice::from_ref(&a));
+    let from = aid(20);
+    f.queue.set(
+        a.id,
+        vec![snapshot(1, 0, InputSource::agent(from), "Main", "first")],
+    );
+    // Agent left Idle (default): even the head is only queued, not in-progress.
+
+    let out = f
+        .usecase
+        .execute(GetProjectWorkStateInput { project: f.project })
+        .await
+        .unwrap();
+
+    assert_eq!(out.agents[0].tickets[0].status, TicketWorkStatus::Queued);
+}
+
+#[tokio::test]
+async fn workstate_ignores_queue_for_agent_absent_from_manifest() {
+    let a = agent(10, "alpha");
+    let f = fixture(std::slice::from_ref(&a));
+    // A queue exists for an agent that is not in the manifest: it must not surface.
+    f.queue.set(
+        aid(999),
+        vec![snapshot(1, 0, InputSource::Human, "User", "ghost")],
+    );
+
+    let out = f
+        .usecase
+        .execute(GetProjectWorkStateInput { project: f.project })
+        .await
+        .unwrap();
+
+    assert_eq!(out.agents.len(), 1);
+    assert!(out.agents[0].tickets.is_empty());
+}
+
+#[tokio::test]
+async fn workstate_truncates_task_preview_and_keeps_original_len() {
+    let a = agent(10, "alpha");
+    let f = fixture(std::slice::from_ref(&a));
+    // 400 chars with runs of whitespace to normalise; well over the 160 cap.
+    let long_task = format!("start{}end", "  x  ".repeat(80));
+    let original_len = long_task.chars().count();
+    f.queue.set(
+        a.id,
+        vec![snapshot(1, 0, InputSource::Human, "User", &long_task)],
+    );
+
+    let out = f
+        .usecase
+        .execute(GetProjectWorkStateInput { project: f.project })
+        .await
+        .unwrap();
+
+    let ticket = &out.agents[0].tickets[0];
+    assert_eq!(ticket.task_preview.chars().count(), 160);
+    assert!(!ticket.task_preview.contains("  "), "whitespace normalised");
+    assert_eq!(ticket.task_len, original_len);
+    assert!(ticket.task_len > 160);
+}
+
+#[tokio::test]
+async fn workstate_maps_human_and_agent_ticket_sources() {
+    let a = agent(10, "alpha");
+    let f = fixture(std::slice::from_ref(&a));
+    let from = aid(20);
+    f.queue.set(
+        a.id,
+        vec![
+            snapshot(1, 0, InputSource::Human, "User", "from human"),
+            snapshot(2, 1, InputSource::agent(from), "Main", "from agent"),
+        ],
+    );
+
+    let out = f
+        .usecase
+        .execute(GetProjectWorkStateInput { project: f.project })
+        .await
+        .unwrap();
+
+    let tickets = &out.agents[0].tickets;
+    assert_eq!(tickets[0].source, TicketWorkSource::Human);
+    assert_eq!(tickets[0].requester_label, "User");
+    assert_eq!(
+        tickets[1].source,
+        TicketWorkSource::Agent { agent_id: from }
+    );
+    assert_eq!(tickets[1].requester_label, "Main");
+}