feat(i18n): add static pre-rendering for multi-language support

- Add `generate-i18n-pages.mjs` script to pre-render localized HTML files at build time
- Add `generate-sitemap.mjs` script to generate language-aware sitemap.xml
- Create `navbar-simple.html` and `footer-simple.html` partials for simple mode
- Update all 80+ tool pages with language routing support
- Expand supported languages to 12: en, de, es, fr, it, pt, tr, vi, id, zh, zh-TW
- Update i18n.ts with new language names and support configuration
- Implement languageRouterPlugin in vite.config.ts for dev server routing
- Update nginx.conf for production static file serving from language directories
- Update TRANSLATION.md with new architecture documentation and language addition guide
- Fix relative paths in 404.html for static deployment compatibility
- Update package.json with new build scripts and dependencies
- Improves SEO through static pre-rendering and proper sitemap generation

src/partials/navbar-simple.html

@@ -0,0 +1,19 @@
+<nav
+  class="bg-gray-800 border-b border-gray-700 sticky top-0 z-30"
+  data-simple-nav="true"
+>
+  <div class="container mx-auto px-4">
+    <div class="flex justify-start items-center h-16">
+      <div class="flex-shrink-0 flex items-center cursor-pointer">
+        <img
+          src="{{baseUrl}}images/favicon-no-bg.svg"
+          alt="Bento PDF Logo"
+          class="h-8 w-8"
+        />
+        <span class="text-white font-bold text-xl ml-2">
+          <a href="{{baseUrl}}">BentoPDF</a>
+        </span>
+      </div>
+    </div>
+  </div>
+</nav>