feat(migration): complete WordPress migration and UX refinements

- Migrate historical posts, localized assets, and 103 comments
- Colocate media into posts/<slug>/images/ and remove wp-content
- Add native bilingual support for ai-can-change post (English default, /zh variant)
- Support clean taxonomy routing (/category/:category and /tag/:tag)
- Dynamically populate categories and tags in sitemap.xml
- Fix header scroll padding/margin offsets for anchor and reference links
- Constrain image and media widths to prevent content overflow
- Redesign homepage recent posts to 4 compact editorial cards
- Restore valid binary favicon.ico and high-res icon assets
- Remove placeholder content and sample test comments

views/pages/post.ejs

@@ -10,7 +10,7 @@
         <span class="meta-sep">&mdash;</span>
         <span>by <%= post.author %></span>
         <% if (post.category) { %>
-          <span>in <a href="/blogs?category=<%= encodeURIComponent(post.category) %>" class="meta-category-link"><%= post.category %></a></span>
+          <span>in <a href="/category/<%= encodeURIComponent(post.category) %>" class="meta-category-link"><%= post.category %></a></span>
         <% } %>
 
         <!-- Inline Bilingual Language Switcher with stable line height -->
@@ -20,7 +20,7 @@
             <span style="opacity: 0.7;">🌐</span>
             <% post.availableLanguages.forEach(l => { 
               const isCurrent = (currentLang === l);
-              const targetUrl = (l === post.defaultLang || (l === 'en' && post.isDefault)) 
+              const targetUrl = (l === post.defaultLang || (post.isDefault && l === post.lang)) 
                 ? `/${post.slug}` 
                 : `/${post.slug}/${l}`;
               const displayLabel = l === 'zh' ? '中文' : (l === 'en' ? 'English' : l.toUpperCase());
@@ -48,7 +48,7 @@
       <div class="post-tags-container">
         <span class="post-tags-label">Tags:</span>
         <% post.tags.forEach(tag => { %>
-          <a href="/blogs?tag=<%= encodeURIComponent(tag.toLowerCase()) %>" class="tag-link">
+          <a href="/tag/<%= encodeURIComponent(tag.toLowerCase()) %>" class="tag-link">
             #<%= tag %>
           </a>
         <% }) %>