Add a vault detail breadcrumb and back-navigation trail to VaultDetail

[1nonlypiece]

📌 Description

src/pages/VaultDetail.tsx is reached from Dashboard, the Vaults list, and the
verifier flows, but offers no breadcrumb showing where the user came from. A
token-styled breadcrumb (Home / Vaults / {vault name}) would orient users and
provide a reliable back path independent of browser history.

🎯 Requirements and Context

• A Breadcrumb component driven by an array of { label, to } segments.
• Last segment is the current page (non-link, aria-current="page").
• Use spacing/typography tokens; truncate the vault name segment with the
  existing truncation helper if very long.
• Wire it into VaultDetail, VaultTransactions, and ValidationDetail.

🛠️ Suggested Execution

1. Fork the repo and create a branch

git checkout -b feature/breadcrumb

2. Implement changes

• New src/components/Breadcrumb.tsx.
• Wire into src/pages/VaultDetail.tsx, src/pages/VaultTransactions.tsx,
  src/pages/ValidationDetail.tsx.
• Tests: src/components/__tests__/Breadcrumb.test.tsx.
• Docs: design-system/documentation/breadcrumb.md.

3. Test and commit

• Run npm test.
• Cover edge cases: single segment, very long current label, missing to,
  aria-current on last item only.

Example commit message

feat: add Breadcrumb component and wire into vault/verifier detail pages

✅ Guidelines

• Minimum 95% test coverage on the new/changed lines.
• Accessible breadcrumb semantics (nav + ordered list).
• Timeframe: 96 hours.

🏷️ Labels

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

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[shinzoxD]

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

I would add a reusable Breadcrumb component with accessible nav/ordered-list semantics, aria-current=page on the final segment, token-based spacing/typography, and long-label truncation. Then I would wire it into VaultDetail, VaultTransactions, and ValidationDetail, with component tests for single-segment, missing to, long labels, and final-segment behavior plus the requested design-system docs.

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