feat(config): add show_animations option to disable canvas animations

[r35krag0th]

Summary

• Adds show_animations: false config flag to completely disable the canvas animation layer
• When disabled: no .canvas-container DOM node is created, the requestAnimationFrame loop never starts, and calling destroy() is triggered on live config change back to false
• Surfaces the toggle in the visual card editor as a boolean switch
• Adds show_animations translation key to all 9 supported locales (en, de, fr, es, it, nl, ru, sk, hu)

Motivation: Canvas weather animations (clouds, sun rays) render light-colored elements over white card text, making it unreadable in certain conditions. Users can now set show_animations: false to get a clean gradient background with no canvas overlay.

card_mod users can also hide animations without this flag:

card_mod:
  style: |
    .canvas-container { display: none; }

Test plan

• Verify show_animations: false hides the canvas and gradient background renders cleanly
• Verify show_animations: true (default/omitted) still shows animations as before
• Verify toggling the option live in the editor destroys/restarts the animation loop correctly
• Verify the toggle appears in the visual editor UI

[r35krag0th]

-.- rebasing to dev; accidentally defaulted to main out of habit.