[tempus2016]

Fixes #1126

The kiosk froze on older iPads once a pet had hatched. #1115 fixed the same freeze for the unhatched egg, but every other pet animation (bounce, sway, wobble, hop, evolve, the laid egg) still ran as a CSS transform on an SVG <g>, and the sleepy mood put a CSS filter on that group. Old iOS Safari repaints an animated SVG group on the main thread every frame.

Fix

• The pet scene is now stacked full-size SVG layers (back, pet, front, laid egg) on the same canvas
• The pet and egg layers sit inside HTML elements, and those carry the animation and the sleepy filter, so Safari moves them on the GPU
• It looks the same: the pivot points are set to the pet's and egg's feet as before

Tested

• Old and new card rendered side by side on a dev Home Assistant (content dog, sleepy dino, proud legendary dragon with full home, accessories and a laid egg), animations paused at the same moments: identical, and every animation now targets an HTML element, none an SVG group
• New render test: no SVG group carries an animated class, and no transform-box or SVG animation/filter in the card styles
• npm run lint clean, npm test 1175/1175