fix(i18n): improve language path handling and prevent unnecessary redirects

- Fix edge cases in path processing for language switching
- Add checks to prevent redirects to the same page
- Update documentation to reflect current project structure

src/components/LanguageSwitcher.tsx

@@ -40,8 +40,10 @@ export default function LanguageSwitcher({ lang: initialLang }: LanguageSwitcher
 
       // Check if the first part of the path is a known language code
       if (currentPathParts.length > 0 && Object.keys(i18nLanguages).includes(currentPathParts[0])) {
+        // If the first part is a language code, remove it to get the base path
         basePath = '/' + currentPathParts.slice(1).join('/');
       } else {
+        // If no language code in path, use the current path as base
         basePath = currentPathname;
       }
       
@@ -49,7 +51,9 @@ export default function LanguageSwitcher({ lang: initialLang }: LanguageSwitcher
       if (!basePath.startsWith('/')) {
         basePath = '/' + basePath;
       }
+      // Fix for empty paths
       if (basePath === '//') basePath = '/';
+      if (basePath === '') basePath = '/';
 
       let newPath;
       // If the target language is the default language and prefixDefaultLocale is false (as per our astro.config.mjs)
@@ -63,9 +67,13 @@ export default function LanguageSwitcher({ lang: initialLang }: LanguageSwitcher
 
       // Clean up double slashes, just in case
       newPath = newPath.replace(/\/\/+/g, '/');
-      if (newPath === '') newPath = '/'; // Handle case where basePath might be empty resulting in just /zh or /en
-
-      window.location.href = newPath;
+      // Handle case where basePath might be empty resulting in just /zh or /en
+      if (newPath === '') newPath = '/';
+      
+      // Prevent unnecessary redirects to the same page
+      if (newPath !== currentPathname) {
+        window.location.href = newPath;
+      }
     }
   };