feat!: Refine lifecycle hooks; fix abortSignal

- add `stop` method. agent can be reused after stopped
- agent can not be reused after disposed
- extension DO NOT exposes `dispose` anymore. only `stop`.
- update panel for new `stop` method
- fix MultiPageAgent dispose event
- better handling abortSignal

packages/ui/src/i18n/locales.ts

@@ -12,6 +12,7 @@ const enUS = {
 			question: 'Question: {{question}}',
 			waitingPlaceholder: 'Waiting for task to start...',
 			stop: 'Stop',
+			close: 'Close',
 			expand: 'Expand history',
 			collapse: 'Collapse history',
 			step: 'Step {{number}} · {{time}}{{duration}}',
@@ -59,6 +60,7 @@ const zhCN = {
 			question: '询问: {{question}}',
 			waitingPlaceholder: '等待任务开始...',
 			stop: '终止',
+			close: '关闭',
 			expand: '展开历史',
 			collapse: '收起历史',
 			step: '步骤 {{number}} · {{time}}{{duration}}',