refactor: enhance LanguageSwitcher and PhotoSwipe initialization

- Simplified LanguageSwitcher logic for better readability and performance.
- Updated PhotoSwipe initialization to clean up existing instances before creating a new one, ensuring smoother transitions.
- Changed event listener for PhotoSwipe to trigger on page load, improving responsiveness.
- Revised theme configuration description and updated site URL for clarity.

src/components/LanguageSwitcher.astro

@@ -35,11 +35,9 @@ document.addEventListener('astro:page-load', () => {
     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}`
   })