fix: 修复无法正确复制公式、mermaid 图表等内容

Author: codexu

src/app/core/main/chat/chat-send.tsx

@@ -337,7 +337,7 @@ export const ChatSend = forwardRef<{ sendChat: () => void }, ChatSendProps>(({ i
       if (quoteData) {
         const { fileName, startLine, endLine, fullContent } = quoteData
         let lineInfo = ''
-        let hasValidLineNumbers = startLine !== -1 && endLine !== -1
+        const hasValidLineNumbers = startLine !== -1 && endLine !== -1
 
         if (hasValidLineNumbers) {
           if (startLine === endLine) {

src/app/core/main/editor/markdown/tiptap-editor.tsx

@@ -81,6 +81,7 @@ const PasteMarkdown = Extension.create({
   },
 })
 
+
 // 简单的启发式函数：检查文本是否看起来像 Markdown
 function looksLikeMarkdown(text: string): boolean {
   return (
@@ -343,6 +344,29 @@ export function TipTapEditor({
     }
   }, [editor])
 
+  // Handle copy event to output Markdown format
+  useEffect(() => {
+    if (!editor) return
+
+    const handleCopy = (event: ClipboardEvent) => {
+      // Get the selected content as Markdown
+      const markdown = editor.getMarkdown()
+
+      // Write Markdown to clipboard
+      if (event.clipboardData) {
+        event.clipboardData.setData('text/plain', markdown)
+        event.preventDefault()
+      }
+    }
+
+    const dom = editor.view.dom
+    dom.addEventListener('copy', handleCopy as EventListener)
+
+    return () => {
+      dom.removeEventListener('copy', handleCopy as EventListener)
+    }
+  }, [editor])
+
   // Handle AI Polish - improve selected text (with streaming and suggestion mode)
   const handleAIPolish = useCallback(async () => {
     if (!editor) return