fix: Resolve Google Search Console indexing issues

根本原因分析：
1. 404错误（36页）- sitemap.xml硬编码了不存在的URL
2. about.html和projects.html位置错误

解决方案：
1. 添加about.html到根目录（从/archive/复制）
2. 添加projects.html到根目录（Portfolio页面）
3. 重构sitemap.xml：
   - 移除硬编码的URL引用
   - 使用Jekyll动态页面发现
   - 排除/archive/、/.git/、/doc/等目录
   - 自动适配实际存在的页面

影响：
- 修复36个404错误
- sitemap仅包含真实可访问的页面
- 提升Google爬虫效率和索引质量

技术细节：
- 保留canonical标签配置（head.html:112）
- "47个备用页面with canonical"是正常行为（分页、标签页等）
- 6个"已爬取未索引"页面需要内容质量优化（后续处理）

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

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

Author: calderbuild

about.html

@@ -0,0 +1,48 @@
+---
+layout: page
+title: "About"
+description: "Meet Jason - AI technology researcher, intelligent Agent development expert, and award-winning innovator from Beijing Information Science & Technology University. Discover his journey in artificial intelligence, full-stack development, and groundbreaking hackathon projects including MeetSpot, L'Oréal Data Intelligence Assistant, and Neighborly Help. Explore his technical expertise in machine learning, LLM applications, Agent architecture design, and modern web development. Learn about his passion for creating intelligent solutions that solve real-world problems and his commitment to advancing AI technology through innovation and collaboration."
+header-img: "img/bg-me-2022.jpg"
+header-mask: 0.3
+multilingual: true
+---
+
+{% include multilingual-sel.html %}
+
+<!-- Chinese Version -->
+<div class="zh post-container">
+    {% capture about_zh %}{% include about/zh.md %}{% endcapture %}
+    {{ about_zh | markdownify }}
+</div>
+
+<!-- English Version -->
+<div class="en post-container">
+    {% capture about_en %}{% include about/en.md %}{% endcapture %}
+    {{ about_en | markdownify }}
+</div>
+
+
+{% if site.disqus_username %}
+<!-- disqus 评论框 start -->
+<div class="comment">
+    <div id="disqus_thread" class="disqus-thread">
+
+    </div>
+</div>
+<!-- disqus 评论框 end -->
+
+<!-- disqus 公共JS代码 start (一个网页只需插入一次) -->
+<script type="text/javascript">
+    /* * * CONFIGURATION VARIABLES * * */
+    var disqus_shortname = "{{site.disqus_username}}";
+    var disqus_identifier = "{{site.disqus_username}}/{{page.url}}";
+    var disqus_url = "{{site.url}}{{page.url}}";
+
+    (function () {
+        var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
+        dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
+        (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
+    })();
+</script>
+<!-- disqus 公共JS代码 end -->
+{% endif %}