refactor: restructure project configuration and utility modules

- Move configuration and utility files to more organized locations
- Update import paths across the project to reflect new file structure
- Simplify content and internationalization utilities
- Remove redundant configuration files and consolidate logic
- Add prefetch configuration to Astro config for improved performance

src/components/LanguageSwitcher.astro

@@ -1,56 +0,0 @@
----
-import themeConfig from '@/config'
-
-// Language array with empty string as default locale
-const langs = ['', ...themeConfig.global.moreLocale]
-const currentLocale = themeConfig.global.locale
-
-function getLanguageDisplayName(code: string) {
-  if (!code)
-return 'Default'
-  return new Intl.DisplayNames(['en'], { type: 'language' }).of(code) || code
-}
----
-
-<button
-  id="language-switcher"
-  class="absolute right-25.6 top-20 z-99 aspect-square w-6.6 c-secondary active:scale-92"
-  aria-label="Switch Language"
-  title={`Current Language: ${getLanguageDisplayName(currentLocale)}`}
->
-  <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" class="h-full w-full">
-    <path d="M19 21 12.3 2h-1L4.7 21l-2.5.2v.8h6.3v-.8L5.7 21l2-5.9h7.5l2 5.9-3.3.2v.8h7.9v-.8zM8 14.3l3.4-10.1 3.5 10.1z" fill="currentColor" />
-  </svg>
-  <span class="sr-only">Switch Language</span>
-</button>
-
-<script is:inline define:vars={{ langs }}>
-// Move event binding into astro:page-load event
-document.addEventListener('astro:page-load', () => {
-  const langSwitch = document.getElementById('language-switcher')
-
-  langSwitch?.addEventListener('click', () => {
-    const { pathname, search, hash } = window.location
-    const segments = pathname.split('/').filter(Boolean)
-    const firstSegment = segments[0] || ''
-    // Check if first segment is a valid language code
-    const currentLang = langs.includes(firstSegment) ? firstSegment : ''
-    // Get next language in rotation (empty string means default locale)
-    const currentIndex = langs.indexOf(currentLang)
-    const nextLang = langs[(currentIndex + 1) % langs.length]
-    const newPath = buildNewPath(currentLang, nextLang, segments, pathname) || '/'
-    window.location.href = `${newPath}${search}${hash}`
-  })
-})
-
-// Handle path construction for both cases:
-// 1. Current path has language prefix
-// 2. Current path has no language prefix
-function buildNewPath(currentLang, nextLang, segments, pathname) {
-  if (currentLang) {
-    segments[0] = nextLang || segments[0]
-    return nextLang ? `/${segments.join('/')}` : `/${segments.slice(1).join('/')}`
-  }
-  return nextLang ? `/${nextLang}${pathname}` : pathname
-}
-</script>