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/app-tauri/src/dto.rs

@@ -9,8 +9,9 @@
 use serde::{Deserialize, Serialize};
 
 use application::{
-    AppError, CreateProjectInput, CreateProjectOutput, GitGraphOutput, HealthInput, HealthReport,
-    LayoutKind, ListProjectsOutput, LiveSessionKind, OpenProjectOutput, ProjectWorkState,
+    AgentTicketState, AppError, CreateProjectInput, CreateProjectOutput, GitGraphOutput,
+    HealthInput, HealthReport, LayoutKind, ListProjectsOutput, LiveSessionKind, OpenProjectOutput,
+    ProjectWorkState, TicketWorkSource, TicketWorkStatus,
 };
 use domain::{AgentBusyState, Project, ProjectId};
 
@@ -1503,6 +1504,87 @@ pub struct LiveWorkSessionDto {
     pub kind: LiveWorkSessionKindDto,
 }
 
+/// Derived processing status of a queued ticket.
+#[derive(Debug, Clone, Copy, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub enum TicketWorkStatusDto {
+    /// The agent's current busy turn is running this ticket.
+    InProgress,
+    /// Waiting behind the head / the agent is idle.
+    Queued,
+}
+
+impl From<TicketWorkStatus> for TicketWorkStatusDto {
+    fn from(status: TicketWorkStatus) -> Self {
+        match status {
+            TicketWorkStatus::InProgress => Self::InProgress,
+            TicketWorkStatus::Queued => Self::Queued,
+        }
+    }
+}
+
+/// Origin of a queued ticket (human operator or a delegating agent).
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase", tag = "kind")]
+pub enum TicketWorkSourceDto {
+    /// The human operator.
+    Human,
+    /// Another agent delegating via `idea_ask_agent`.
+    #[serde(rename_all = "camelCase")]
+    Agent {
+        /// The delegating agent id.
+        agent_id: String,
+    },
+}
+
+impl From<TicketWorkSource> for TicketWorkSourceDto {
+    fn from(source: TicketWorkSource) -> Self {
+        match source {
+            TicketWorkSource::Human => Self::Human,
+            TicketWorkSource::Agent { agent_id } => Self::Agent {
+                agent_id: agent_id.to_string(),
+            },
+        }
+    }
+}
+
+/// One queued/in-progress delegation ticket for an agent.
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct AgentTicketStateDto {
+    /// Stable id of the queued ticket.
+    pub ticket_id: String,
+    /// Conversation thread this task enters.
+    pub conversation_id: String,
+    /// FIFO position at snapshot time (`0` = head).
+    pub position: u32,
+    /// Derived status (in-progress vs queued).
+    pub status: TicketWorkStatusDto,
+    /// Origin of the ticket.
+    pub source: TicketWorkSourceDto,
+    /// Display label of the requester.
+    pub requester_label: String,
+    /// Bounded excerpt of the task.
+    pub task_preview: String,
+    /// Character length of the original (un-truncated) task.
+    pub task_len: usize,
+}
+
+impl From<AgentTicketState> for AgentTicketStateDto {
+    fn from(ticket: AgentTicketState) -> Self {
+        Self {
+            ticket_id: ticket.ticket_id.to_string(),
+            conversation_id: ticket.conversation_id.to_string(),
+            position: ticket.position,
+            status: ticket.status.into(),
+            source: ticket.source.into(),
+            requester_label: ticket.requester_label,
+            task_preview: ticket.task_preview,
+            task_len: ticket.task_len,
+        }
+    }
+}
+
 /// One manifest agent's current live/busy state.
 #[derive(Debug, Clone, Serialize)]
 #[serde(rename_all = "camelCase")]
@@ -1517,6 +1599,8 @@ pub struct AgentWorkStateDto {
     pub live: Option<LiveWorkSessionDto>,
     /// Current mediated-input busy state.
     pub busy: AgentBusyState,
+    /// Pending/in-progress delegation tickets, in FIFO order.
+    pub tickets: Vec<AgentTicketStateDto>,
 }
 
 /// Project-level read model for conversation/delegation UX.
@@ -1543,6 +1627,11 @@ impl From<ProjectWorkState> for ProjectWorkStateDto {
                         kind: live.kind.into(),
                     }),
                     busy: agent.busy,
+                    tickets: agent
+                        .tickets
+                        .into_iter()
+                        .map(AgentTicketStateDto::from)
+                        .collect(),
                 })
                 .collect(),
         }

crates/app-tauri/src/state.rs

@@ -993,6 +993,10 @@ impl AppState {
         // partagé pour `resolve`/`resolve_ticket`/`cancel_head` côté orchestrateur.
         let inmemory_mailbox = Arc::new(InMemoryMailbox::new());
         let mailbox = Arc::clone(&inmemory_mailbox) as Arc<dyn domain::mailbox::AgentMailbox>;
+        // Same concrete mailbox, second (read-only) port view for the work-state
+        // read model: lists pending tickets without touching the mutating surface.
+        let queue_snapshot =
+            Arc::clone(&inmemory_mailbox) as Arc<dyn domain::mailbox::AgentQueueSnapshot>;
         let mediated_inbox = Arc::new(
             MediatedInbox::with_pty(
                 Arc::clone(&inmemory_mailbox),
@@ -1031,6 +1035,7 @@ impl AppState {
             Arc::clone(&contexts_port),
             Arc::clone(&live_sessions),
             Arc::clone(&input_mediator),
+            queue_snapshot,
         ));
 
         // --- Limites de session des agents (ARCHITECTURE §21, LS7) ---

crates/app-tauri/tests/dto_agents.rs

@@ -9,8 +9,9 @@ use app_tauri_lib::dto::{
 };
 use application::AppError;
 use application::{
-    AgentWorkState, CreateAgentOutput, InspectConversationOutput, LaunchAgentOutput,
-    ListAgentsOutput, LiveSessionKind, LiveWorkSession, ProjectWorkState,
+    AgentTicketState, AgentWorkState, CreateAgentOutput, InspectConversationOutput,
+    LaunchAgentOutput, ListAgentsOutput, LiveSessionKind, LiveWorkSession, ProjectWorkState,
+    TicketWorkSource, TicketWorkStatus,
 };
 use domain::ids::{AgentId, NodeId, ProfileId, SessionId};
 use domain::ports::ConversationDetails;
@@ -219,6 +220,7 @@ fn project_work_state_dto_serialises_live_and_busy_camelcase() {
                 ticket,
                 since_ms: 1_234,
             },
+            tickets: vec![],
         }],
     });
 
@@ -231,11 +233,77 @@ fn project_work_state_dto_serialises_live_and_busy_camelcase() {
     assert_eq!(v["agents"][0]["busy"]["state"], "busy");
     assert_eq!(v["agents"][0]["busy"]["ticket"], ticket.to_string());
     assert_eq!(v["agents"][0]["busy"]["sinceMs"], 1_234);
+    assert_eq!(v["agents"][0]["tickets"], json!([]));
     assert!(v["agents"][0].get("agent_id").is_none());
     assert!(v["agents"][0]["live"].get("session_id").is_none());
     assert!(v["agents"][0]["busy"].get("since_ms").is_none());
 }
 
+#[test]
+fn project_work_state_dto_serialises_tickets_camelcase() {
+    let agent = AgentId::from_uuid(Uuid::from_u128(11));
+    let profile = ProfileId::from_uuid(Uuid::from_u128(12));
+    let requester = AgentId::from_uuid(Uuid::from_u128(20));
+    let head_ticket = domain::TicketId::from_uuid(Uuid::from_u128(30));
+    let next_ticket = domain::TicketId::from_uuid(Uuid::from_u128(31));
+    let conversation = domain::ConversationId::from_uuid(Uuid::from_u128(40));
+    let dto = app_tauri_lib::dto::ProjectWorkStateDto::from(ProjectWorkState {
+        agents: vec![AgentWorkState {
+            agent_id: agent,
+            name: "Worker".to_owned(),
+            profile_id: profile,
+            live: None,
+            busy: domain::AgentBusyState::Idle,
+            tickets: vec![
+                AgentTicketState {
+                    ticket_id: head_ticket,
+                    conversation_id: conversation,
+                    position: 0,
+                    status: TicketWorkStatus::InProgress,
+                    source: TicketWorkSource::Agent {
+                        agent_id: requester,
+                    },
+                    requester_label: "Main".to_owned(),
+                    task_preview: "Analyser le module".to_owned(),
+                    task_len: 842,
+                },
+                AgentTicketState {
+                    ticket_id: next_ticket,
+                    conversation_id: conversation,
+                    position: 1,
+                    status: TicketWorkStatus::Queued,
+                    source: TicketWorkSource::Human,
+                    requester_label: "User".to_owned(),
+                    task_preview: "Vérifier".to_owned(),
+                    task_len: 8,
+                },
+            ],
+        }],
+    });
+
+    let v = serde_json::to_value(&dto).unwrap();
+    let head = &v["agents"][0]["tickets"][0];
+    assert_eq!(head["ticketId"], head_ticket.to_string());
+    assert_eq!(head["conversationId"], conversation.to_string());
+    assert_eq!(head["position"], 0);
+    assert_eq!(head["status"], "inProgress");
+    assert_eq!(head["source"]["kind"], "agent");
+    assert_eq!(head["source"]["agentId"], requester.to_string());
+    assert_eq!(head["requesterLabel"], "Main");
+    assert_eq!(head["taskPreview"], "Analyser le module");
+    assert_eq!(head["taskLen"], 842);
+    // snake_case must not leak.
+    assert!(head.get("ticket_id").is_none());
+    assert!(head.get("task_preview").is_none());
+    assert!(head["source"].get("agent_id").is_none());
+
+    let next = &v["agents"][0]["tickets"][1];
+    assert_eq!(next["status"], "queued");
+    assert_eq!(next["source"]["kind"], "human");
+    assert!(next["source"].get("agentId").is_none());
+    assert_eq!(next["requesterLabel"], "User");
+}
+
 #[test]
 fn launch_agent_request_carries_conversation_id_for_resume() {
     let raw = json!({