[Frontend] Respect prefers-reduced-motion and add a sound and animation mute setting

[grantfox-oss]

Telegram (ask questions / claim the issue here first): https://t.me/+DOylgFv1jyJlNzM0

Why this matters

The gamification (kingdom) area uses animations and src/app/utils/soundManager.ts plays sounds. There is no respect for the prefers-reduced-motion system setting and no user control to mute sound or reduce motion. This is an accessibility and comfort gap for a feature that is otherwise delightful.

Acceptance criteria

• Honor prefers-reduced-motion to disable or tone down non-essential animation
• Add a settings toggle for sound and one for reduced motion, persisted via the store
• soundManager respects the mute setting and never autoplays loudly on load
• Confirm the gamification views remain usable with motion and sound off

Files to touch

• src/app/utils/soundManager.ts
• src/app/components/gamification/
• src/app/[locale]/kingdom/page.tsx
• src/app/[locale]/settings/page.tsx
• src/app/stores/useUIStore.ts

Out of scope

• New gamification mechanics

[david87131]

Hi please can you give me issue

[fahatadam]

Good day maintainer, can you please assign me to work on this.

[grantfox-oss]

🦊 GrantFox — @fahatadam has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #21)
2. Your PR will be reviewed by the LabsCrypt maintainers

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