Add a Toast/Snackbar store and provider wired to the toast z-index token

[1nonlypiece]

📌 Description

There is a toast z-index token but no runtime toast system. Wallet
connect/disconnect, copy-to-clipboard, and validation actions currently have no
transient feedback surface. This issue adds a Zustand-backed toast store and a
ToastViewport that renders queued toasts.

🎯 Requirements and Context

• A Zustand store with push, dismiss, auto-expiry, and a max-visible cap.
• A ToastViewport using the toast z-index token and aria-live="polite".
• Success/error/info variants mapped to color tokens.
• Respect prefers-reduced-motion for enter/exit.

🛠️ Suggested Execution

1. Fork the repo and create a branch

git checkout -b feature/toast-store

2. Implement changes

• New src/Zustand/toastStore.ts and src/components/ToastViewport.tsx.
• Mount viewport in src/components/Layout.tsx.
• Tests: src/Zustand/__tests__/toastStore.test.ts,
  src/components/__tests__/ToastViewport.test.tsx.
• Docs: design-system/documentation/toast.md.

3. Test and commit

• Run npm test.
• Cover edge cases: auto-expiry timers, manual dismiss, max-visible overflow,
  duplicate ids, reduced-motion path.

Example commit message

feat: add toast store and viewport using the toast z-index token

✅ Guidelines

• Minimum 95% test coverage on the new/changed lines.
• Live-region announcements; reduced-motion aware.
• Timeframe: 96 hours.

🏷️ Labels

type-feature · area-frontend · MAYBE REWARDED · GRANTFOX OSS · OFFICIAL CAMPAIGN

💬 Community & Support

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[shinzoxD]

Hi maintainers, I would like to take this issue if it is available.

I would add the Zustand-backed toast store with push, dismiss, auto-expiry, and max-visible behavior, render a ToastViewport with the existing toast z-index token and aria-live=polite, map success/error/info variants to color tokens, and respect reduced-motion for transitions. I would add timer/overflow/duplicate-id/reduced-motion tests and document the API in the design-system docs.

I will wait for assignment or GrantFox confirmation before opening a PR.