feat: initial release of pengzhan.dev personal editorial blog platform

- Editorial web platform built with Node.js, Express, EJS, and Vanilla CSS
- Markdown content engine with YAML frontmatter, bilingual variants, and hot-reload watcher
- Unified SQLite with FTS5 search indexing, query logging, and schema filters
- Centered editorial post layout with margin-docked left TOC and mobile bottom sheet
- WordPress-grade comment system with moderation dashboard and bulk operations under /guanli
- Complete SEO suite (JSON-LD structured data, RSS/Atom feeds, XML sitemap, robots.txt)
- CI/CD workflows for linting, security audits (Gitleaks), automated tests, and Docker releases

sample-content/plugins/seo-analyzer/index.js

@@ -0,0 +1,15 @@
+module.exports = {
+  onPostLoad({ post }) {
+    const raw = post.rawContent || '';
+    const internalMatches = raw.match(/\[[^\]]+\]\((\/[^)]+)\)/g) || [];
+    const externalMatches = raw.match(/\[[^\]]+\]\((https?:\/\/[^)]+)\)/g) || [];
+
+    post.seoMetrics = {
+      internalLinkCount: internalMatches.length,
+      externalLinkCount: externalMatches.length,
+      hasMetaDescription: Boolean(post.excerpt && post.excerpt.length > 30),
+      titleLength: post.title.length,
+      isTitleOptimal: post.title.length >= 25 && post.title.length <= 70
+    };
+  }
+};