fix: 修复 Markdown 代码块渲染导致的 HTML hydration 错误

- 移除客户端状态管理，改为服务端渲染
- 添加 pre 组件处理代码块的包裹样式
- 修改 code 组件只返回 <code> 元素，避免重复渲染
- 添加 p 组件块级元素检测，防止 <p><pre> 嵌套
- 使用 className 和换行符检测区分 inline code 和代码块

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/components/project/MarkdownContent.tsx

@@ -1,10 +1,8 @@
-'use client'
-
+import React from 'react'
 import ReactMarkdown from 'react-markdown'
 import remarkGfm from 'remark-gfm'
 import rehypeRaw from 'rehype-raw'
 import rehypeSanitize from 'rehype-sanitize'
-import { useState, useEffect } from 'react'
 import type { Components } from 'react-markdown'
 
 interface MarkdownContentProps {
@@ -25,6 +23,14 @@ function generateHeadingId(text: string): string {
     .replace(/-+$/, '')             // Trim - from end
 }
 
+// Helper function to escape HTML
+function escapeHtml(code: string): string {
+  return code
+    .replace(/&/g, '&')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+}
+
 // Custom GitHub-style components
 const components: Components = {
   // Headings with anchor links
@@ -81,12 +87,26 @@ const components: Components = {
     </h4>
   ),
 
-  // Paragraphs
-  p: ({ children, ...props }) => (
-    <p className="mb-4 leading-7" {...props}>
-      {children}
-    </p>
-  ),
+  // Paragraphs - skip wrapping if contains block-level elements like pre
+  p: ({ children, node, ...props }: any) => {
+    // Check if the paragraph node contains block-level elements in its children
+    // This uses the AST node data from react-markdown
+    const hasBlockElement = node?.children?.some((child: any) => {
+      const tagName = child?.tagName
+      // Check if any direct child is a block-level element
+      return ['pre', 'table', 'blockquote', 'ul', 'ol', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'div', 'img', 'hr'].includes(tagName)
+    })
+
+    if (hasBlockElement) {
+      return <>{children}</>
+    }
+
+    return (
+      <p className="mb-4 leading-7" {...props}>
+        {children}
+      </p>
+    )
+  },
 
   // Lists
   ul: ({ children, className, ...props }) => (
@@ -111,9 +131,24 @@ const components: Components = {
     </li>
   ),
 
-  // Code blocks with syntax highlighting
+  // Code blocks (pre element wrapper)
+  pre: ({ children, ...props }: any) => {
+    return (
+      <pre className="bg-gray-900 dark:bg-gray-950 text-gray-100 p-4 rounded-lg overflow-x-auto my-4 border border-gray-700" {...props}>
+        {children}
+      </pre>
+    )
+  },
+
+  // Code elements (both inline and in code blocks)
   code: ({ inline, className, children, ...props }: any) => {
-    if (inline) {
+    // If inline is explicitly true, or if there's no language class and no newlines, treat as inline
+    const hasLanguageClass = className && typeof className === 'string' && className.startsWith('language-')
+    const childStr = String(children)
+    const hasNewlines = childStr.includes('\n')
+    const isInline = inline === true || (!hasLanguageClass && !hasNewlines)
+
+    if (isInline) {
       return (
         <code
           className="px-1.5 py-0.5 rounded bg-gray-100 dark:bg-gray-800 text-sm font-mono border border-gray-300 dark:border-gray-600"
@@ -124,10 +159,11 @@ const components: Components = {
       )
     }
 
-    const language = className?.replace(/language-/, '') || 'text'
-
+    // For code blocks, just return the code element - the pre wrapper will be added by react-markdown
     return (
-      <SyntaxHighlighterWrapper language={language} code={String(children).trim()} />
+      <code className="text-sm font-mono" {...props}>
+        {children}
+      </code>
     )
   },
 
@@ -202,44 +238,12 @@ const components: Components = {
         checked={checked}
         readOnly
         className="mr-2 h-4 w-4 rounded border-gray-300"
+        name="task-item"
         {...props}
       />
     ) : null,
 }
 
-// Syntax highlighter wrapper (will use Shiki for server-side, Prism for client)
-function SyntaxHighlighterWrapper({ language, code }: { language: string; code: string }) {
-  const [highlighted, setHighlighted] = useState<string | null>(null)
-
-  useEffect(() => {
-    // For now, use simple highlighting with proper escaping
-    // In production, you'd want to use Shiki or Prism for better highlighting
-    const escaped = code
-      .replace(/&/g, '&amp;')
-      .replace(/</g, '&lt;')
-      .replace(/>/g, '&gt;')
-
-    setHighlighted(escaped)
-  }, [code])
-
-  if (!highlighted) {
-    return (
-      <pre className="bg-gray-900 dark:bg-gray-950 text-gray-100 p-4 rounded-lg overflow-x-auto my-4 border border-gray-700">
-        <code className="text-sm font-mono">{code}</code>
-      </pre>
-    )
-  }
-
-  return (
-    <pre className="bg-gray-900 dark:bg-gray-950 text-gray-100 p-4 rounded-lg overflow-x-auto my-4 border border-gray-700">
-      <code
-        className="text-sm font-mono"
-        dangerouslySetInnerHTML={{ __html: highlighted }}
-      />
-    </pre>
-  )
-}
-
 export function MarkdownContent({ content, className = '' }: MarkdownContentProps) {
 
   if (!content || content.trim() === '') {