feat(gallery): enhance close button accessibility

Add .navClose styles for 30% min-width, right alignment, and pointer cursor.
Apply class to close div in mobile gallery nav for consistent keyboard support.

Signed-off-by: Sped0n <hi@sped0n.com>

assets/ts/mobile/galleryNav.tsx

@@ -37,7 +37,7 @@ export default function GalleryNav(props: {
           <span class="num">{indexLength()[2]}</span>
           <span class="num">{indexLength()[3]}</span>
         </div>
-        <div onClick={onClick} onKeyDown={onClick}>
+        <div class="navClose" onClick={onClick} onKeyDown={onClick}>
           {capitalizeFirstLetter(props.closeText)}
         </div>
       </div>