fix: preserve markdown when saving notes

Change the chat text-selection Add to notes action to use the existing markdown selection payload, matching Add to chat formatting behavior while still falling back to plain text when markdown extraction is unavailable.

Stop distilling or summarizing selected text before saving it to project notes. The action now appends the selected content directly so code, lists, emphasis, and other markdown survive.

Increase the project notes text limit from 1000 to 3000 characters to account for saving raw selected text instead of a short generated summary.

Update user-facing copy across locales from distilled insight language to selected text language.

packages/ui/src/lib/i18n/messages/zh-CN.ts

@@ -1448,7 +1448,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.questionCard.copyFailed': '复制问题失败',
   'chat.textSelection.toast.noProject': '未找到此会话对应的项目',
   'chat.textSelection.toast.addToNotesFailed': '添加到笔记失败',
-  'chat.textSelection.toast.addToNotesSuccess': '已将洞察添加到笔记',
+  'chat.textSelection.toast.addToNotesSuccess': '已将选中文本添加到笔记',
   'chat.textSelection.toast.addToNotesSummaryFailed': '无法总结所选内容，已将所选文本添加到笔记',
   'chat.textSelection.actions.addToChat': '添加到聊天',
   'chat.textSelection.actions.newSession': '新建会话',
@@ -1456,7 +1456,7 @@ export const dict: Record<I18nKey, string> = {
   'chat.textSelection.actions.addToNotes': '添加到笔记',
   'chat.textSelection.title.addToCurrentChat': '添加到当前聊天',
   'chat.textSelection.title.newSessionWithSelection': '使用选中内容创建新会话',
-  'chat.textSelection.title.saveInsightToNotes': '将洞察保存到笔记',
+  'chat.textSelection.title.saveInsightToNotes': '将选中文本保存到笔记',
   'chat.messageBody.actions.revertAria': '回退到这条消息',
   'chat.messageBody.actions.revert': '从此处回退',
   'chat.messageBody.actions.forkAria': '从这条消息分叉',