Redesign media card with album art, 7-button transport, and Wolf Kit icons

Replace media card with full redesign: rectangular album art (180px) with
background fetcher, track title + artist display, volume icon + percentage,
progress bar, and 7-button transport row (playlist, skip-back, seek-back,
play/pause, seek-forward, skip-forward, search) with Apple-style opacity
focus. Add scroll-wheel seek and back-button card mode exit.

Replace all media SVG icons with Wolf Kit Rounded Line icons from SVGRepo
(CC Attribution, author: thewolfkit): play, pause, skip-back, skip-forward,
seek-back, seek-forward, playlist (line-3), search, volume.

Fix vacuum card: add config fallback for custom button cards, expand entity
subscriptions for derived entities, fix clean command segment format, remove
fill, increase image size to 160px.

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

assets/ui-icons/skip-forward.svg

@@ -0,0 +1,4 @@
+<svg width="128" height="128" color="#fff" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path fill-rule="evenodd" clip-rule="evenodd" d="M6.1094 4.20444C4.78029 3.31836 3 4.27115 3 5.86854V18.1315C3 19.7289 4.78029 20.6817 6.1094 19.7956L15.3066 13.6641C16.4941 12.8725 16.4941 11.1276 15.3066 10.3359L6.1094 4.20444ZM5 5.86854L14.1972 12L5 18.1315V5.86854Z" fill="currentColor"/>
+<path d="M21 5C21 4.44772 20.5523 4 20 4C19.4477 4 19 4.44772 19 5V19C19 19.5523 19.4477 20 20 20C20.5523 20 21 19.5523 21 19V5Z" fill="currentColor"/>
+</svg>