feat(agent): messagerie inter-agents via send_blocking (D6) — §17

Comble le trou historique : un agent qui en interroge un autre reçoit enfin
le CONTENU de la réponse, plus seulement un ACK de cycle de vie.

- domain : OrchestratorCommand::AskAgent { target, task } + action wire
  agent.message (target+task requis) ; DomainEvent::AgentReplied
  { agent_id, reply_len } (bus I/O-free, le contenu remonte par l'outcome).
- application : OrchestratorOutcome gagne reply: Option<String>. Méthode
  ask_agent (§17.4) — cible structurée vivante ⇒ send_blocking direct ;
  cible morte ⇒ LaunchAgent structuré puis send ; agent vivant en PTY ou
  profil sans structured_adapter ⇒ Invalid (non adressable, jamais d'ACK
  trompeur) ; agent inconnu ⇒ NotFound ; service non câblé ⇒ Invalid.
  Timeout (300s) ⇒ erreur typée SANS tuer la session. Succès ⇒ publie
  AgentReplied + reply: Some(content). Injection additive via builders
  with_structured / with_events (call sites legacy intacts).
- app-tauri : state câble with_structured/with_events ; DTO AgentReplied.

Tests (QA) : +14 verts (11 app + 3 domaine), invariants validés par
mutation test (reply!=None, timeout ne shutdown pas). cargo test
--workspace : 817 passed, 0 failed.

Suivi (D6b) : surfacer reply dans le writer wire .response.json
(infrastructure/orchestrator) pour la délégation par protocole fichier.
Reste D7 : menu restreint Claude/Codex + retrait custom.

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

crates/app-tauri/src/events.rs

@@ -47,6 +47,14 @@ pub enum DomainEventDto {
         /// Exit code.
         code: i32,
     },
+    /// A target agent produced a synchronous reply to an inter-agent `ask` (§17.4).
+    #[serde(rename_all = "camelCase")]
+    AgentReplied {
+        /// Target agent id.
+        agent_id: String,
+        /// Reply length in bytes (metric, not the payload).
+        reply_len: usize,
+    },
     /// An agent's runtime profile was changed (hot-swap of the AI engine).
     #[serde(rename_all = "camelCase")]
     AgentProfileChanged {
@@ -179,6 +187,13 @@ impl From<&DomainEvent> for DomainEventDto {
                 agent_id: agent_id.to_string(),
                 code: *code,
             },
+            DomainEvent::AgentReplied {
+                agent_id,
+                reply_len,
+            } => Self::AgentReplied {
+                agent_id: agent_id.to_string(),
+                reply_len: *reply_len,
+            },
             DomainEvent::AgentProfileChanged {
                 agent_id,
                 profile_id,

crates/app-tauri/src/state.rs

@@ -710,16 +710,22 @@ impl AppState {
         // the UI drives (IdeA stays the single source of truth for the agent/skill
         // lifecycle). The per-project watcher that feeds it is started lazily when
         // a project is opened (see `ensure_orchestrator_watch`).
-        let orchestrator_service = Arc::new(OrchestratorService::new(
-            Arc::clone(&create_agent),
-            Arc::clone(&launch_agent),
-            Arc::clone(&list_agents),
-            Arc::clone(&close_terminal),
-            Arc::clone(&update_agent_context),
-            Arc::clone(&create_skill),
-            Arc::clone(&profile_store_port),
-            Arc::clone(&terminal_sessions),
-        ));
+        let orchestrator_service = Arc::new(
+            OrchestratorService::new(
+                Arc::clone(&create_agent),
+                Arc::clone(&launch_agent),
+                Arc::clone(&list_agents),
+                Arc::clone(&close_terminal),
+                Arc::clone(&update_agent_context),
+                Arc::clone(&create_skill),
+                Arc::clone(&profile_store_port),
+                Arc::clone(&terminal_sessions),
+            )
+            // Messagerie inter-agents §17.4 : registre structuré + bus pour
+            // `agent.message` (AskAgent) — rendez-vous synchrone via send_blocking.
+            .with_structured(Arc::clone(&structured_sessions))
+            .with_events(Arc::clone(&events_port)),
+        );
 
         // --- Windows (L10) ---
         let move_tab = Arc::new(MoveTabToNewWindow::new(