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

server/services/content.js

@@ -145,6 +145,7 @@ class ContentService {
         defaultPost.availableLanguages = availableLangs;
         for (const v of Object.values(variants)) {
           v.availableLanguages = availableLangs;
+          v.defaultLang = defaultPost.lang;
         }
 
         this.postsBySlug.set(slug, {

server/services/db.js

@@ -80,6 +80,37 @@ class DatabaseService {
       CREATE INDEX IF NOT EXISTS idx_comments_email ON comments(author_email);
     `);
 
+    // Auto-seed comments if comments table is newly created and comments.json exists
+    try {
+      const count = this.db.prepare('SELECT COUNT(*) as c FROM comments').get().c;
+      const seedFile = path.join(dataDir, 'comments.json');
+      if (count === 0 && fs.existsSync(seedFile)) {
+        const seedData = JSON.parse(fs.readFileSync(seedFile, 'utf8'));
+        const insertStmt = this.db.prepare(`
+          INSERT INTO comments (id, post_slug, author_name, author_email, author_website, body, created_at, approved, ip)
+          VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+        `);
+        this.db.exec('BEGIN');
+        for (const c of seedData) {
+          insertStmt.run(
+            c.id,
+            c.post_slug,
+            c.author_name,
+            c.author_email,
+            c.author_website,
+            c.body,
+            c.created_at,
+            c.approved,
+            c.ip || ''
+          );
+        }
+        this.db.exec('COMMIT');
+        console.log(`[DB] Seeded ${seedData.length} comments from ${seedFile}`);
+      }
+    } catch (err) {
+      console.warn('[DB] Warning: Failed to auto-seed comments:', err.message);
+    }
+
     console.log(`[DB] Unified SQLite database initialized at ${this.dbPath}`);
   }