feat(app): add chat outline navigation (#2792)

* feat(app): add chat outline navigation

Long agent sessions need prompt navigation without coupling viewport movement to disposable server windows. Keep fetched timeline pages in client state so repeated jumps stay local, and settle prompt jumps against virtualized row measurement changes.

* fix(app): preserve chat outline timeline coverage

* fix(app): reconcile outline window submissions

* fix(app): harden outline timeline navigation

packages/app/src/i18n/resources/pt-BR.ts

@@ -190,6 +190,7 @@ export const ptBR: TranslationResources = {
   agentStream: {
     empty: "Comece a conversar com este agente...",
     scrollToBottom: "Rolar para o fim",
+    historyLoadFailed: "Não foi possível carregar o histórico do agente",
     permission: {
       plan: "Plano",
       required: "Permissão necessária",
@@ -1812,6 +1813,10 @@ export const ptBR: TranslationResources = {
       detailLevel: {
         title: "Nível de detalhe",
       },
+      chatOutline: {
+        title: "Estrutura do chat",
+        description: "Mostrar uma estrutura para navegar entre prompts",
+      },
       fonts: {
         title: "Fontes",
         systemDefault: "Sistema padrão",