add text high contrast mode for accessibility

src/lib/components/chat/Settings/Tools.svelte

@@ -90,7 +90,10 @@
 					</div>
 
 					<div class="my-1.5">
-						<div class="text-xs text-gray-500">
+						<div
+							class={`text-xs 
+								${($settings?.highContrastMode ?? false) ? 'text-gray-800 dark:text-gray-100' : 'text-gray-500'}`}
+						>
 							{$i18n.t('Connect to your own OpenAPI compatible external tool servers.')}
 							<br />
 							{$i18n.t(