fix(chat): le transcript s'affiche à nouveau après redémarrage automatique d'un agent — #295 (app-tauri ChatBridge: cartes successors/owners, rebind_session déplace sink+scrolloback du logical chat vers la session de remplacement et canonical_session résout les écritures avec l'ancien id sur toutes les opérations register/scrollback/detach/send_output; backend stream: ReplayOutputBridge::rekey prépare le scrollback source devant le destination et invalide les générations pré-rekey des deux pumps; commands: agent_send binde l'owner stable (projectId,agentId) au tour humain et rebind avant le flux de continuation au handoff restart; reattach_agent_chat résout le successeur du bridge puis fallback identité stable projectId/agentId explicite ou owner bindé, renvoie sessionId effectif + conversationId, NOT_FOUND sinon; web-server chat.attach même fallback stale→live par project/agent; DTO ReattachChatDto/ReattachResultDto documentent l'id effectif post-restart; frontend: ReattachAgentChatOptions, conversationId dans ChatAttachedPayload, CustomAgentChatView réattache sur agentRestartCompleted (dédupe par restartId, scrollback appliqué, tours restart préservés), retry identité stable sur NOT_FOUND dans openOrAttach avant fallback launch frais, publication sessionId effectif + conversationId, état vide «Conversation liée» quand une conversation/run/workstate lié existe; QA verte reconfirmée par Git: git diff --check, cargo fmt --all --check, app-tauri chat_bridge 34/34 dont 3 nouveaux restart_rebind + dto_chat 24/24, cargo check -p app-tauri, backend 91+7 ignored permissions socket, web-server websocket_chat_attach 3/3, npm test 77/77 CustomAgentChatView+agentGateway, npm run build; réserves non bloquantes: warnings Vite esbuild/oxc et chunk >500kB connus)

crates/app-tauri/tests/chat_bridge.rs

@@ -550,6 +550,84 @@ fn reattach_repaints_scrollback_and_preserves_it_without_resend() {
     );
 }
 
+#[test]
+fn restart_rebind_preserves_transcript_and_routes_old_id_writes_to_replacement() {
+    let bridge = ChatBridge::new();
+    let previous = sid();
+    let replacement = sid();
+    let sink = Arc::new(Mutex::new(Vec::new()));
+    let generation = bridge.register(previous, capturing_channel(Arc::clone(&sink)));
+
+    assert!(bridge.send_output(&previous, delta("before restart")));
+    bridge.rebind_session(previous, replacement);
+
+    assert_eq!(bridge.successor(&previous), replacement);
+    assert_eq!(
+        bridge.scrollback(&replacement),
+        vec![delta("before restart")]
+    );
+    assert!(
+        bridge.send_output(&previous, delta("after restart")),
+        "the in-flight old pump must reach the rekeyed live sink"
+    );
+    assert_eq!(
+        bridge.scrollback(&replacement),
+        vec![delta("before restart"), delta("after restart")]
+    );
+    assert_eq!(sink.lock().unwrap().len(), 2);
+
+    bridge.detach_if(&previous, generation);
+    assert!(
+        !bridge.send_output(&replacement, delta("detached")),
+        "the old pump generation detaches the migrated sink"
+    );
+    assert_eq!(bridge.scrollback(&previous).len(), 3);
+}
+
+#[test]
+fn restart_rebind_moves_stable_owner_to_the_replacement_session() {
+    let bridge = ChatBridge::new();
+    let previous = sid();
+    let replacement = sid();
+    let project = domain::ProjectId::from_uuid(Uuid::from_u128(10));
+    let agent = domain::AgentId::from_uuid(Uuid::from_u128(20));
+    bridge.bind_owner(previous, project, agent);
+
+    bridge.rebind_session(previous, replacement);
+
+    assert_eq!(bridge.owner(&previous), Some((project, agent)));
+    assert_eq!(bridge.owner(&replacement), Some((project, agent)));
+}
+
+#[test]
+fn restart_rebind_keeps_a_newer_replacement_sink_and_merges_scrollback_in_order() {
+    let bridge = ChatBridge::new();
+    let previous = sid();
+    let replacement = sid();
+    let old_sink = Arc::new(Mutex::new(Vec::new()));
+    let new_sink = Arc::new(Mutex::new(Vec::new()));
+    let old_generation = bridge.register(previous, capturing_channel(Arc::clone(&old_sink)));
+    assert!(bridge.send_output(&previous, delta("old")));
+    bridge.register(replacement, capturing_channel(Arc::clone(&new_sink)));
+    assert!(bridge.send_output(&replacement, delta("new")));
+
+    bridge.rebind_session(previous, replacement);
+
+    assert_eq!(
+        bridge.scrollback(&replacement),
+        vec![delta("old"), delta("new")]
+    );
+    assert!(bridge.send_output(&previous, delta("continued")));
+    assert_eq!(old_sink.lock().unwrap().len(), 1);
+    assert_eq!(new_sink.lock().unwrap().len(), 2);
+
+    bridge.detach_if(&previous, old_generation);
+    assert!(
+        bridge.send_output(&replacement, delta("still attached")),
+        "the old pump must not detach a channel already attached to the replacement"
+    );
+}
+
 #[test]
 fn detach_view_keeps_session_scrollback_and_later_reattach_replays_absent_chunks() {
     let bridge = ChatBridge::new();

crates/app-tauri/tests/dto_chat.rs

@@ -363,6 +363,7 @@ fn import_chat_attachments_request_response_use_camel_case() {
 fn reattach_chat_dto_serialises_camel_case_with_typed_scrollback() {
     let dto = ReattachChatDto {
         session_id: "sess-1".into(),
+        conversation_id: Some("conv-1".into()),
         scrollback: vec![
             ReplyChunk::UserPrompt {
                 text: "Hi".into(),
@@ -380,6 +381,7 @@ fn reattach_chat_dto_serialises_camel_case_with_typed_scrollback() {
         v,
         json!({
             "sessionId": "sess-1",
+            "conversationId": "conv-1",
             "scrollback": [
                 { "kind": "userPrompt", "text": "Hi" },
                 { "kind": "textDelta", "text": "Hi" },
@@ -394,10 +396,12 @@ fn reattach_chat_dto_serialises_camel_case_with_typed_scrollback() {
 fn reattach_chat_dto_empty_scrollback_is_empty_array() {
     let dto = ReattachChatDto {
         session_id: "s".into(),
+        conversation_id: None,
         scrollback: vec![],
     };
     let v = serde_json::to_value(&dto).unwrap();
     assert_eq!(v["scrollback"], json!([]));
+    assert!(v.get("conversationId").is_none());
 }
 
 // ---------------------------------------------------------------------------