Add a fixed, decorative layer of soft clouds that slowly float across
the Habbo sky behind the content:
- Five clouds at staggered sizes, heights, opacities and loop timings
(60s–190s) so the drift feels organic.
- Dimmed further in dark mode; frozen by prefers-reduced-motion.
- Pure decoration: aria-hidden, pointer-events: none, no color
utilities in markup (cloud shapes live in globals.css).