fix(AccountCard): add clipboard error handling and memoize avatar hashing (#889)

[bamiebot-maker]

Description

Resolves #889.

Problem

1. In src/components/AccountCard.tsx (AccountCard), the copy-to-clipboard button silently failed without visual feedback when navigator.clipboard.writeText rejected in non-HTTPS or permission-restricted environments.
2. The avatar generator recomputed avatar initials and color arrays on every parent re-render rather than memoizing against the account public key.
3. Avatar hash calculation produced identical color gradients for accounts with identical first 6 characters because prefix-only or truncated values were evaluated.

Solution & Implementation

• Clipboard Error Handling & Fallback:
  • Enhanced AddressDisplay with an onCopyError callback invoked when both navigator.clipboard.writeText and document.execCommand('copy') fail.
  • Implemented copyToClipboard fallback utility handling synchronous and asynchronous clipboard rejection.
  • Wired onCopyError in AccountCard to display an error toast ("Copy Failed": "Failed to copy address to clipboard.").
• Full Public Key Avatar Hashing:
  • Implemented 32-bit FNV-1a hash algorithm (fnv1aHash) that evaluates every character of the full public key string, guaranteeing distinct hashes and gradient palettes for accounts that share identical prefixes.
• Memoization:
  • Memoized avatar initials and avatar gradient styles in AccountCard and AccountCardCompact using useMemo(..., [address]), preventing style recalculation when non-account props (e.g. onNavigate) change.
• Unit Testing:
  • Added unit tests in src/components/AccountCard.test.tsx verifying:
    • Error toast is displayed when clipboard write fails.
    • Success toast is displayed when clipboard write succeeds.
    • copyToClipboard fallback behavior across modern Clipboard API and execCommand.
    • Full-key hashing avoids prefix collisions for accounts with identical first 6 characters.
    • Gradient consistency across renders and memoization when non-account props change.

Acceptance Criteria Checklist

• Clipboard write failures display an error toast message.
• Avatar hash calculation uses the full public key string.
• Component does not recompute gradient styles when non-account props change.
• Unit tests cover copy failure scenarios and avatar consistency.

[drips-wave]

@bamiebot-maker Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits