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

licensing.html

@@ -310,7 +310,7 @@
             <p class="mt-4 text-sm text-gray-400 italic text-center">
               💡 Custom requests and development are available for separate
               charges.
-              <a href="/contact.html" class="text-indigo-400 hover:underline"
+              <a href="contact.html" class="text-indigo-400 hover:underline"
                 >Contact us</a
               >
               for details.
@@ -471,7 +471,7 @@
           <p class="text-gray-400 text-sm">
             Still not sure?
             <a
-              href="/contact.html"
+              href="contact.html"
               class="text-indigo-400 hover:underline font-semibold"
               >Contact us</a
             >
@@ -797,7 +797,7 @@
                 >. <br /><br />
                 If you have specific requirements or want a custom licensing
                 arrangement, feel free to
-                <a href="/contact.html" class="text-indigo-400 hover:underline"
+                <a href="contact.html" class="text-indigo-400 hover:underline"
                   >contact us</a
                 >
                 with details about your use case, company size, and deployment
@@ -995,7 +995,7 @@
           We're here to help. Reach out to discuss your licensing needs.
         </p>
         <a
-          href="/contact.html"
+          href="contact.html"
           class="inline-block px-8 py-3 rounded-full bg-gradient-to-b from-indigo-500 to-indigo-600 text-white font-semibold focus:ring-2 focus:ring-offset-2 focus:ring-offset-gray-900 focus:ring-indigo-400 hover:shadow-xl hover:shadow-indigo-500/30 transition-all duration-200 transform hover:-translate-y-1"
         >
           Contact Us