fix: LanguageSwitcher sets cookie before activation and uses href navigation

- Write cookie before dynamicActivateLocale so the SSR request always
  carries the new locale even if the dynamic import is slow
- Replace window.location.reload() with href navigation to bypass
  browser back-forward cache that can serve stale SSR HTML

Author: angelospk

frontend/src/components/common/LanguageSwitcher/index.tsx

@@ -65,12 +65,13 @@ export const LanguageSwitcher = () => {
                 }))}
                 defaultValue={getClientLocale()}
                 placeholder={t`English`}
-                onChange={(value) =>
-                    dynamicActivateLocale(value as string).then(() => {
-                        document.cookie = `locale=${value};path=/;max-age=31536000`;
-                        // this shouldn't be necessary, but it is due to the wide use of t`...` in the codebase
-                        window.location.reload();
-                    })}
+                onChange={(value) => {
+                    if (!value) return;
+                    document.cookie = `locale=${value};path=/;max-age=31536000`;
+                    dynamicActivateLocale(value).finally(() => {
+                        window.location.href = window.location.pathname + window.location.search;
+                    });
+                }}
             />
         </>
     )