fix(settings): navigate to About tab when clicking update badge

- Add defaultTab prop to SettingsPage for external tab control
- UpdateBadge click now opens settings directly to About tab
- Settings button still opens to General tab (default behavior)
- Change update badge text from version number to "Update available"

src/components/UpdateBadge.tsx

@@ -41,7 +41,7 @@ export function UpdateBadge({ className = "", onClick }: UpdateBadgeProps) {
     >
       <Download className="w-3 h-3 text-blue-500 dark:text-blue-400" />
       <span className="text-gray-700 dark:text-gray-300 font-medium">
-        v{updateInfo.availableVersion}
+        {t("settings.updateBadge")}
       </span>
       <button
         onClick={(e) => {