fix(backend,orchestrator,chat): l'objectif suspendu guide le premier tour post-restart — #290 regression partielle (register_suspended_turn capture la demande utilisateur exacte au point d'entrée chat agent_send/chat.send avec source diagnostique, RestartRendezvousCoordinator conserve tour/objectif/restart_attempt_id, take_continuation consommable exactement une fois et seulement par la tentative courante: suspended_restart_continuation_prompt place l'objectif utilisateur avant toute consigne generique et StructuredHumanTurnTransition::Resume porte le prompt host-provided injecte au runtime de remplacement; nettoyage du tour suspendu sur succes, echec, annulation et abandon/expiration; diagnostics projet/agent/turn_id/restart_attempt_id/source; rendez-vous inter-agents #289 inchanges; QA verte reconfirmee par Git: cargo check --workspace, backend self_restart_contract_tests 3/3, orchestrator_service restart 10/10, workstate_actions 9/9, app-tauri chat_bridge 31/31, web-server websocket_chat_send 3/3, fmt --check, diff --check; restants: rebuild AppImage + validation live reprise objectif apres restart; carnet #290 iteration regression + passage store qa inclus; scripts/ hors périmètre; aucun push)

crates/backend/src/lib.rs

@@ -1131,7 +1131,9 @@ mod self_restart_contract_tests {
         coordinator.ready(key, &restart_id);
         assert_eq!(
             turn.transition_after_provider_terminal_async().await,
-            StructuredHumanTurnTransition::Resume,
+            StructuredHumanTurnTransition::Resume {
+                prompt: application::suspended_restart_continuation_prompt("restart me"),
+            },
             "the old provider terminal is a control transition, not the human Final"
         );
         coordinator
@@ -1453,7 +1455,10 @@ pub enum StructuredHumanTurnTransition {
     /// No self-restart owns this terminal event; it is authoritative for the UI.
     Complete,
     /// The old terminal event is superseded; continue on the replacement runtime.
-    Resume,
+    Resume {
+        /// Host-provided first prompt for the replacement runtime.
+        prompt: String,
+    },
     /// Replacement failed explicitly.
     Failed(String),
     /// The user cancelled the logical turn while replacement was in flight.
@@ -1470,6 +1475,29 @@ impl StructuredHumanTurnGuard {
         project_id: ProjectId,
         agent_id: AgentId,
         prompt: &str,
+    ) -> Self {
+        Self::start_with_source(
+            input,
+            mailbox,
+            restart_rendezvous,
+            project_id,
+            agent_id,
+            prompt,
+            "direct_human_chat",
+        )
+    }
+
+    /// Starts a direct human turn while retaining its exact restart objective and
+    /// diagnostic entry-point source in application state.
+    #[must_use]
+    pub fn start_with_source(
+        input: Arc<dyn domain::input::InputMediator>,
+        mailbox: Arc<dyn domain::mailbox::AgentMailbox>,
+        restart_rendezvous: Arc<application::RestartRendezvousCoordinator>,
+        project_id: ProjectId,
+        agent_id: AgentId,
+        prompt: &str,
+        source: &str,
     ) -> Self {
         let agent = domain::RuntimeAgentKey::new(project_id, agent_id);
         let ticket_id = domain::mailbox::TicketId::new_random();
@@ -1486,7 +1514,14 @@ impl StructuredHumanTurnGuard {
             agent,
             ticket_id,
             armed: Arc::new(std::sync::atomic::AtomicBool::new(owns_turn)),
-            restart: owns_turn.then(|| restart_rendezvous.register(agent)),
+            restart: owns_turn.then(|| {
+                restart_rendezvous.register_suspended_turn(
+                    agent,
+                    ticket_id.to_string(),
+                    prompt.to_owned(),
+                    source.to_owned(),
+                )
+            }),
             finish_on_drop: true,
         }
     }
@@ -1527,8 +1562,16 @@ impl StructuredHumanTurnGuard {
                     }
                 }
                 application::RestartRendezvousState::Ready { restart_id } => {
+                    let prompt = restart.take_continuation(&restart_id).map_or_else(
+                        || application::SELF_RESTART_CONTINUATION_PROMPT.to_owned(),
+                        |continuation| {
+                            application::suspended_restart_continuation_prompt(
+                                &continuation.objective_text,
+                            )
+                        },
+                    );
                     restart.accept_ready(&restart_id);
-                    return StructuredHumanTurnTransition::Resume;
+                    return StructuredHumanTurnTransition::Resume { prompt };
                 }
                 application::RestartRendezvousState::Failed { message, .. } => {
                     return StructuredHumanTurnTransition::Failed(message);