feat(pwa): 实现PWA支持，支持离线访问

- 添加 manifest.json 文件配置PWA应用信息
- 创建 Service Worker (sw.js) 实现资源缓存与离线访问
- 在HTML中引入PWA相关meta标签及注册代码
- 更新项目文档结构说明，增加PWA相关文件描述
- 移除冗余CSS样式并优化页面加载逻辑
- 调整Google Analytics和51.LA统计脚本加载方式
- 完善部署文档中的PWA自定义配置说明

about.html

@@ -5,6 +5,10 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, viewport-fit=cover">
     <title>关于我 - Honesty</title>
     <meta http-equiv="X-UA-Compatible" content="ie=edge">
+    <!-- PWA相关配置 -->
+    <meta name="theme-color" content="#6c5ce7">
+    <link rel="manifest" href="/manifest.json">
+    
     <!--SEO信息 -->
     <meta name="description" content="关于Honesty,关于HeHouHui,关于HeHui,关于明厚, About Me Honesty, About Me HeHouHui, About Me HeHui">
     <meta name="keywords" content="Honesty,HeHouHui,HeHui,明厚">
@@ -41,6 +45,8 @@
     <link rel="stylesheet" href="https://cdn.bootcdn.net/ajax/libs/artalk/2.9.1/Artalk.css">
     <link rel="stylesheet" href="css/artalk.css?version=20251125">
     <link rel="icon" href="favicon.ico">
+    <link rel="apple-touch-icon" href="./images/logo.png">
+    
     <!--IE淘汰计划-->
     <script>
         if (/*@cc_on!@*/false || (!!window.MSInputMethodContext && !!document.documentMode)) window.location.href = "https://imsyy.top/upgrade-your-browser/index.html?referrer=" + encodeURIComponent(window.location.href);
@@ -424,5 +430,34 @@
         initFormatter();
     }
 </script>
+
+<!-- PWA注册 -->
+<script>
+    if ('serviceWorker' in navigator) {
+        window.addEventListener('load', function() {
+            navigator.serviceWorker.register('/js/sw.js')
+                .then(function(registration) {
+                    console.log('SW registered: ', registration);
+                })
+                .catch(function(registrationError) {
+                    console.log('SW registration failed: ', registrationError);
+                });
+        });
+    }
+</script>
+
+<!-- Apple PWA支持 -->
+<meta name="apple-mobile-web-app-capable" content="yes">
+<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
+<meta name="apple-mobile-web-app-title" content="Honesty">
+<link rel="apple-touch-icon" href="/apple-touch-icon.png">
+
+<!-- Windows PWA支持 -->
+<meta name="msapplication-TileImage" content="/images/avatar.jpeg">
+<meta name="msapplication-TileColor" content="#6c5ce7">
+<meta name="msapplication-tap-highlight" content="no">
+
+<!-- 其他PWA相关meta标签 -->
+<meta name="mobile-web-app-capable" content="yes">
 </body>
 </html>