fix(blog): resolve 'Missing parameter: tag' build error and enhance international tag support

- Refactor [slugifyTag](cci:1://file:///Volumes/DATA/Astro/astro-batavia/src/i18n/utils.ts:86:0-96:1) utility to support non-ASCII characters (e.g., Japanese tags) and handle special symbols gracefully.
- Update `getStaticPaths` in tag pages to filter out empty slugs, preventing Astro's "Missing parameter" build failure.
- Ensure tag slugs are unique within each language to avoid routing conflicts.
- Clean up accidental code duplication in the localized blog tag route.

Author: leonism

src/pages/[lang]/blog/tags/[tag].astro

@@ -94,96 +94,3 @@ const pageProps = {
     )}
   </div>
 </Layout>
-
----
-import { getCollection, type CollectionEntry } from 'astro:content';
-import Layout from '@/layouts/Layout.astro';
-import BlogCard from '@/components/blog/BlogCard.astro';
-import { useTranslations, slugifyTag } from '@/i18n/utils';
-import { ui } from '@/i18n/ui';
-
-export async function getStaticPaths() {
-  const allPosts = await getCollection('blog');
-  const uniqueTags = [...new Set(allPosts.flatMap(post => post.data.tags || []))];
-  const languages = ['es', 'ja']; // en is handled separately
-
-  return languages.flatMap(lang => {
-    const paths = uniqueTags
-      .map(tag => {
-        const slug = slugifyTag(tag);
-        return {
-          params: { lang, tag: slug },
-          props: { tag }
-        };
-      })
-      .filter(path => path.params.tag.length > 0);
-
-    // Eliminate duplicate slugs per language
-    return Array.from(new Map(paths.map(p => [p.params.tag, p])).values());
-  });
-}
-
-const { tag } = Astro.props;
-const { lang } = Astro.params;
-const t = useTranslations(lang as keyof typeof ui);
-
-// Get blog posts for this language and tag
-const posts = await getCollection('blog', ({ id, data }: CollectionEntry<'blog'>) => {
-  if (!id.startsWith(`${lang}/`) || data.draft) return false;
-  if (!data.tags) return false;
-
-  return data.tags.some(t => slugifyTag(t) === Astro.params.tag);
-});
-
-// Sort posts by publication date (newest first)
-const sortedPosts = posts.sort(
-  (a: CollectionEntry<"blog">, b: CollectionEntry<"blog">) =>
-    b.data.pubDate.valueOf() - a.data.pubDate.valueOf()
-);
-
-const postsPerPage = 9;
-const totalPages = Math.ceil(sortedPosts.length / postsPerPage);
-const postsToDisplay = sortedPosts.slice(0, postsPerPage);
-
-const pageProps = {
-  postsPerPage,
-  totalPages,
-  lang,
-};
----
-
-<Layout
-  {...pageProps}
-  title={`#${tag} | ${t('nav.blog')} | Astro Batavia`}
-  description={lang === 'es' ? `Artículos sobre ${tag}` : lang === 'ja' ? `${tag}に関する記事` : `Articles about ${tag}`}
-  lang={lang}
->
-  <div class="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
-    <!-- Header -->
-    <div class="text-center mb-12">
-      <h1 class="text-4xl sm:text-5xl font-bold text-gray-900 dark:text-gray-100 mb-4">
-        #{tag}
-      </h1>
-      <p class="text-xl text-gray-600 dark:text-gray-300 max-w-3xl mx-auto">
-        {lang === 'es' ? `Artículos etiquetados con #${tag}` : lang === 'ja' ? `#${tag} のタグが付いた記事` : `Articles tagged with #${tag}`}
-      </p>
-    </div>
-
-    <!-- Posts Grid -->
-    {postsToDisplay.length > 0 ? (
-      <div id="posts-container" class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-8 mb-12">
-        {postsToDisplay.map((post: CollectionEntry<'blog'>) => (
-          <div class="post-item animate-fade-in">
-            <BlogCard post={post} lang={lang} />
-          </div>
-        ))}
-      </div>
-    ) : (
-      <div class="text-center py-12">
-        <p class="text-gray-500 dark:text-gray-400">
-          {lang === 'es' ? 'No se encontraron artículos.' : lang === 'ja' ? '記事が見つかりません。' : 'No articles found.'}
-        </p>
-      </div>
-    )}
-  </div>
-</Layout>