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/zh-CN.ts

@@ -190,6 +190,7 @@ export const zhCN: TranslationResources = {
   agentStream: {
     empty: "开始和这个 Agent 对话...",
     scrollToBottom: "滚动到底部",
+    historyLoadFailed: "无法加载智能体历史记录",
     permission: {
       plan: "Plan",
       required: "需要权限",
@@ -1760,6 +1761,10 @@ export const zhCN: TranslationResources = {
       detailLevel: {
         title: "详细程度",
       },
+      chatOutline: {
+        title: "聊天大纲",
+        description: "显示用于在提示词之间跳转的大纲",
+      },
       fonts: {
         title: "字体",
         systemDefault: "系统默认",