fix: artist hero uses <img> with responsive object-position for better crop

Switching from background-image (inline JS, single position for all sizes)
to an <img> element lets CSS media queries apply different object-position:
- Mobile: center top (portrait images show face in upper portion)
- Desktop: center 30% (wide banner, lower anchor avoids showing only hair)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

styles.css

@@ -824,10 +824,12 @@ button:focus{outline:none}
 .artist-hero{height:220px;border-radius:14px;overflow:hidden;position:relative;margin-bottom:24px;background:linear-gradient(135deg,var(--surface2),var(--surface))}
 .artist-hero-overlay{position:absolute;inset:0;background:linear-gradient(to right,rgba(7,7,15,.85) 0%,transparent 100%);display:flex;align-items:flex-end;padding:20px 28px}
 .artist-hero-name{font-size:32px;font-weight:800;letter-spacing:-1px}
+.artist-hero-img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;object-position:center top;display:block}
 @media(min-width:769px){
   .artist-hero{height:320px;border-radius:16px}
   .artist-hero-overlay{padding:28px 36px}
   .artist-hero-name{font-size:46px;letter-spacing:-2px}
+  .artist-hero-img{object-position:center 30%}
 }
 
 /* ── MISC ── */